L  I  B  HAR.Y 

OF  THE 

U  N  IVER.SITY 

OF    ILLINOIS 


■NATURAL- HISTORY   SURVE 

550.5 
FI 

v.£,cop.2. 


Return  this  book  on  or  before  the 
Latest  Date  stamped  below. 

Theft,  mutilation,  and  underlining  of  books 
are  reasons  for  disciplinary  action  and  may 
result  in  dismissal  from  the  University. 
University  of  Illinois  Library 


JON    7  lb 


L161  —  O-1096 


Field  Columbian  Museum 

Publication  78. 
Geological  Series.  Vol.  II,  No.  3. 


ON  THE 

OSTEOLOGY    OF    NYCTOSAURUS 

(NYCTODACTYLUS), 


WITH  NOTES  ON 


AMERICAN    PTEROSAURS. 


BY 


Samuel   W.  Williston,  M.D.,  Ph.D. 

Associate  Curator,  Division  of  Paleontology 

Professor  of  Paleontology,  University  of  Chicago. 


Oliver  Cummings  Farrington,  Ph.D. 
Curator  of  Geology. 


Chicago,  U.  S.  A. 
June  1,  1903. 


ON    THE    OSTEOLOGY   OF   NYCTOSAURUS   (NYCTODAC- 
TYLUS),  WITH  NOTES  ON  AMERICAN  PTEROSAURS. 


BY   SAMUEL   W.  WILLISTON. 


In  previous  papers*  I  have  given  a  summary  of  the  principal  characters 
of  the  genus  Nyctosaurus,\  with  more  or  less  complete  descriptions  of  cer- 
tain parts  of  the  skeleton.  In  the  present  paper  I  give  a  more  detailed 
description  of  the  skeleton,  based  upon  the  unusually  well-preserved  and 
nearly  complete  specimen  collected  by  Mr.  H.  T.  Martin,  together  "with 
some  remarks  upon  the  relationships  and  habits  of  the  American 
pterosaurs,  and  the  description  of  a  new  genus  and  species  from  the 
Lower  Cretaceous  of  Kansas. 

The  specimen  herewith  described  is  of  unusual  importance,  as  throw- 
ing much  light  upon  the  structure,  not  only  of  the  American  pterodactyls, 
but  also  upon  certain  characters  of  the  European  ones.  It  is,  I  believe, 
for  purposes  of  study  the  most  complete  specimen  of  this  order  of  reptiles 
now  known,  comprising  as  it  does  nearly  every  bone  in  the  skeleton,  for 
the  most  part  associated  in  their  natural  relations.  The  specimen  now 
forms  a  part  of  the  collections  of  the  Field  Columbian  Museum. 

SKULL. 

A  full  description,  with  illustrations,  of  the  skull  has  been  given  in  the 
Journal  of  Geology,  vol.  x,  1902,  p.  520.  I  give  herewith  illustrations 
of  the  mandible,  not  there  figured.  A  careful  measurement  of  the 
sides  of  this  bone  a  little  in  front  of  the  posterior  end  of  the  symphysis, 
where  they  are  the  broadest,  obtained  by  measuring  each  fractured  portion, 
gives  a  width  for  each  side  of  twenty-four  millimeters.  The  correspond- 
ing width  of  the  palate  is  twenty-eight  millimeters.  This  would  give,  as 
the  greatest  depth  of  the  mandible,  near  the  end  of  the  symphysis, 
about  twenty  millimeters. 

♦Kansas  University  Quarterly,  vol.  i,  p.  5,  1892. 

American  Journal  of  Anatomy,  vol.  1,  p.  297,  1902. 

Journal  of  Geology,  vol.  x,  p.  520,  iqo2. 

Text  Book  of  Paleontology,  Zittel  (Eastman),  vol.  ii,  p.  255,  f.  361. 

tThis  genus  has  generally  been  known  as  Nyetodactylus.  (See  synonymy  beyond.)  Marsh 
changed  the  name  because  of  the  supposed  preoccupation  of  the  name  Nyctosaurus.  In  this  he 
was  not  justified.  The  name  has  never  been  used  otherwise  for  a  genus  of  animals.  Doubtless  he 
thought  the  term  conflicted  with  Nyctisauria,  used  for  a  group  of  sauria.  It  does  not,  however, 
according  to  the  accepted  canons  of  nomenclature,  and  the  original  name  should  not  be  displaced. 

Field  Col.  Mus.,  Geol.  Ser.,  Vol.  II,  No.  3. 


126 


Field  Columbian  Museum — Geology,  Vol.  II. 


Fig.  i.    Mandible  of  Nyctosaurus gracilis,  x  %.    i,  from  above;  2,  from  below. 

MEASUREMENTS   OF    MANDIBLE. 

mm. 

Length,  as  preserved -l6° 

Lengths  of  rami  to  hind  margin  of  floor 78 

Width  between  condyles 39 


HYOIDS. 
Two  slender,  cylindrical,  gently  curved  bones,  about  thirty  millime- 
ters in  length,  were  found  lying  side  by  side  beneath  the  anterior  part  of 
the  skull.  They  are  sufficiently  well  shown  in  Plate  I  of  the  paper  cited 
in  the  Journal  of  Geology.  Lying  near  the  occiput  in  the  same  plate,  is 
seen  a  small,  triangular,  or  V-shaped  bone  which  I  then  thought  might  be 


On  the  Osteology  of  Nyctosaurus.  127 

a  proatlas,  said  by  Zittel  to  occur  in  the  pterodactyls,  but  of  which  there  is 
no  other  evidence  in  this  specimen.  Since  the  removal  of  this  bone  from 
the  matrix,  it  seems  quite  surely  to  be,  rather,  the  anterior,  median  element 
of  the  hyoidean  apparatus.  One  view,  which  I  take  to  be  the  superior, 
is  shown  in  PI.  XLI,  Fig.  6,  three  times  the  natural  size,  and,  in  Fig.  7  of 
the  same  plate,  is  shown  one  of  the  articular  extremities  (a)  from  the  side, 
much  more  enlarged.  The  bone  is  nearly  flat,  with  the  pointed  extremity 
curved  upward,  and  with  the  two  articular  extremities  much  more 
massive  than  the  remainder  of  the  bone;  they  are  also  directed  upward. 
Each  has  a  smooth,  synovial  articular  surface,  doubtless  for  the  articula- 
tion of  the  cylindrical  rods.  On  the  opposite  surface,  near  the  articula- 
tions, there  is  a  slight  longitudinal  ridge,  and  near  the  middle  of  the 
bone  on  each  side,  there  is  an  elongated,  oval  surface,  apparently  for 
muscular  attachment.  The  slender  rods  seem  to  agree  quite  with  the 
hyoidean  bones  of  other  pterodactyls,  but  I  cannot  find  that  the  triangu- 
lar bone  has  ever  been  described. 

VERTEBRAE. 

Seven  has  usually  been  accepted  as  the  number  of  vertebrae  in  the 
neck  of  pterodactyls.  If,  however,  we  consider  that  vertebra  which 
bears  the  first  rib  articulating  with  the  sternum  to  be  the  first  dorsal, 
then  I  believe  that  the  prevailing  number  of  cervicals  in  pterodactyls 
is  eight.  Furbringer  has  already  expressed  the  opinion  that  there  are 
eight  vertebrae  instead  of  seven:*  "Falls  die  Patagiosaurier  zum  Theil 
nur  sieben  Halswirbel  besitzen,  wie  algemein  behauptet  wird,  aber 
meines  Erachtens  erst  noch  zu  erweisen  ist,  so  ware  eventuell  anzu- 
nehmen,  das  dieselben  durch  eine  geringgradige,  kranial  gerichtete 
Wanderung  der  vorderen  Extremitat  ihren  urspriinglich  aus  acht 
Wirbeln  bestehenden  Hals  um  einen  in  das  thorakale  Gebiet  uberge- 
henden  Wirbel  verkurzten."  He  further  expressed  the  opinion  that 
the  vertebra  which  I  had  considered  to  be  the  first  dorsal  in  Pteranodon 
was  really  the  eighth  cervical.  In  a  later  paper  I  stated  that  the  eighth 
vertebra  in  the  neck  of  Nyctosaurus  was  a  functional  cervical,  though  a 
structural  dorsal.  ...  I  have  usually  assigned  this  vertebra  to  the  dorsal 
series  because  of  its  great  structural  differences  from  the  anterior  cervicals; 
but  these  differences  are  scarcely  greater  than  those  of  the  last  cervical  in 
the  turtles.  Owenf  correctly  located  it  in  the  neck.  In  his  description 
of  this  vertebra  in  Dimorphodon  he  says:  "  At  the  base  of  the  neck  or  the 
beginning  of  the  back,  the  vertebrae  suddenly  decrease  in  length;  the 
hypapophysis  disappears,  or  is  represented  only  by  a  slight  projection  of 

*  Jena.    Zeitschr.  f.  Naturwissenchaft,  vol.  xxxiv,  p.  665,  1900. 
t  Paleontograph.  Soc,  i860,  p.  60. 


128  Field  Columbian  Museum — Geology,  Vol.  II. 

the  lower  border  of  the  anterior  cup;  parapophyses  [i.  e.,  exapophyses]  are 
less  produced.  The  lower  surface  of  the  centrum  is  flattened  and  quad- 
rate in  form.  The  parapophysis,  diapophysis  and  rudimental  rib  coalesce 
around  the  vertebrarterial  canal;  an  oblique  ridge  is  continued  from  the 
anterior  zygapophysis  downward  and  outward  upcn  the  pleurapophvsis 
and  behind  the  zygapophysis.  Above  these  developments  the  neural  arch 
contracts  from  before  backward  to  an  extent  of  five  lines,  compared  with 
a  total  vertebral  breadth  anteriorly  of  one  inch,  eight  lines;  it  then  rapidly 
expands,  rising  vertically  at  its  fore  part,  and  developing  at  its  back 
part  the  posterior  zygapophysis,  the  articular  facets  of  which  look  more 
directly  outward  than  in  the  long  cervical  vertebrae;  the  superincumbent 
tubercle  is  more  distinct  from  the  facet;  the  posterior  zygapophyses  are 
also  much  more  approximated  than  in  those  vertebrae." 

It  would  seem  evident  from  this  description,  which  applies  in  the  main 
to  the  corresponding  vertebra  of  the  Kansas  forms,  that  the  eighth  post- 
cranial  vertebra  is  really  a  cervical.  Certainly  we  can  hardly  put  a 
vertebra  with  rudimentary  ribs  at  the  beginning  of  the  dorsal  series! 
Owen  afterwards  ascribed  eight  vertebrae  to  the  neck,  or  seven,  counting 
the  united  axis  and  atlas  as  one.  Quenstedt,  also,  in  1855,  gave  the  num- 
ber as  eight.  O.  Fraas  (Paleontographica,  1878,  p.  166)  found  eight 
vertebrae  in  the  neck  of  Pterodactylus  suevicus,  but  mistook  the  third  for 
the  axis,  thus  counting  only  seven. 

In  my  earliest  paper*  on  Nyctosaurus  I  said:  "The  centra  of  twelve 
vertebrae  are  preserved  from  the  region  back  of  the  neck.  Three  of  these 
are  evidently  anterior  thoracic,  judging  from  their  structure  and  the  posi- 
tion in  which  they  lie.  The  shortest  of  them,  to  which  was  attached  a 
very  large  rib,  and  which  was  lying  in  front  of  the  scapula,  may  represent 
the  first  thoracic  vertebra."  This  specimen  I  have  figured  in  PI.  XLIII, 
Fig.  7,  of  the  present  paper.  The  specimen  is  fortunately  preserved  with 
little  or  no  distortion,  though  a  part  of  the  spine  is  wanting.  As  seen 
from  the  front  (the  view  figured),  the  transverse,  shallowly  concave  cup  is 
straight  or  gently  concave  on  its  upper  margin,  and  convex  below.  Aris- 
ing from  the  front  end  of  the  centrum  there  is,  on  each  side,  a  very  stout 
parapophysis,  with  which  the  head  of  the  rib  referred  to  was  in  apposi- 
tion. On  the  anterior  side  of  this  process,  and  continuous,  or  nearly  so, 
with  the  outer  side  of  the  cup,  there  is  an  oval,  convex  articular  surface 
for  union  with  the  exapophysis.  Above  this  process,  separated  by  a 
notch,  there  is  a  long,  flattened  diapophysis,  for  articulation  with  the 
well-developed  tubercle  of  the  rib.  The  anterior  zygapophyses  are  much 
more  approximated  than  in  the  long  cervical  verterbrae.     Their  articular 

*  Kansas  University  Quarterly,  vol.  i,  p.  o. 


On  the  Osteology  of  Nyctosaurus.  129 

surface  is  oval,  the  plane  of  each  nearly  at  right  angles  with  that  of  its  mate. 
The  spine  is  broad  and  transverse;  from  the  front  it  presents  a  median 
ridge.  On  the  under  side  the  centrum  is  flat,  the  flatness  reaching  nearly 
to  the  extremity  of  the  parapophysis ;  the  width  is  considerably  greater 
than  the  length.  The  posterior  surface  of  the  centrum  in  this  specimen 
is  distinctly  roughened  for  sutural  union  with  the  following  centrum;  the 
posterior  zygapophyses  also  unite  with  the  succeeding  ones  suturally. 
This  vertebra  is  very  clearly  the  first  of  the  notarium,  as  Seeley  has  hap- 
pily called  the  united  dorsal  vertebrae.  "  Two  other  vertebrae  found  close 
by  the  one  described,  and  possibly  one  or  the  other  contiguous  with  it, 
differ  remarkably  in  having  no  or  a  rudamentary  parapophysial  process, 
and  in  having  the  diapophysis  much  shorter."  "In  Pteranodon  there  are 
at  least  four  vertebrae  with  dia-  and  parapophyses."  "  In  two  other 
centra  there  is  a  long,  recurved,  parapophysial  process,  as  though  formed 
by  an  anchylosed  rib,  on  each  side;  they  are  probably  lumbar  vertebrae." 
It  is  very  clear,  however,  that  these  last  two  vertebrae  are  not  lumbars,  but 
separated  elements  of  the  notarium.  Of  the  two  other  vertebrae  men- 
tioned, one  is  probably  the  eighth  cervical,  described  below,  while  the 
other  may  be  the  fourth  dorsal. 

In  Pteranodon,  I  thought  there  might  be  two  vertebrae  intervening 
between  the  elongated  cervicals  and  the  notarium.  "  The  centrum  is  short 
and  broad,  so  different  from  the  preceding  one  that  it  is  possible  there 
may  be  an  intervening  one  lost.  The  ball  is  more  than  four  times  as 
broad  as  high,  concave  on  the  upper  margin,  convex  below.  The  post- 
exapophyses  are  large,  and  confluent  with  the  articular  faces  of  the  ball, 
but  are  concave.  The  convex  pre-exapophyses,  at  the  outer  side  of  the 
cup  are  at  the  base  of  the  lower  root  (that  is  the  parapophysis)  of  the 
elongated  transverse  process."*  This  vertebra  corresponds  with  the 
eighth  post-cranial  vertebra  of  the  present  specimen,  but  an  "imperfect 
vertebra,  evidently  following  the  one  described,  has  the  centrum  very  simi- 
lar, save  that  the  spine  appears  to  be  less  stout."  I  cannot  at  the  present 
time  examine  this  specimen,  but  it  is  probable  that  it  is  the  first  separated 
vertebra  of  the  notarium. 

From  the  foregoing,  then,  it  seems  assured  that  there  is  a  free,  short 
vertebra  in  front  of  the  notarium,  in  both  Pteranodon  and  Nyctosaurus, 
bearing  a  free,  small  rib,  which  does  not  unite  with  the  sternum.  This  ver- 
tebra is  the  eighth  cervical,  and  is  probably  present  in  all  pterodactyls.  It 
is  strange  that  authors,  in  the  description  of  the  neck  bones  of  the  ptero- 
dactyls should  have  so  often  spoken  of  the  united  atlas  and  axis  as  one 
vertebra,  thus  reckoning  seven  instead  of  eight  vertebrae  in  this  part  of  the 

*  Williston,  Kansas  University  Quarterly,  vol.  vi,  p.  40. 


130  Field  Columbian  Museum — Geology,  Vol.  II. 

column.  Von  Ammon*  thus  describes  the  neck  vertebrae  of  Rhamphor- 
hynchus  longicaudatus : 

"  Es  sind  sieben  Halswirbel  vorhanden.  Atlas  and  Epistropheus 
werden  hierbei  als  ein  Wirbel  gerechnet.  Beide  miteinander  zusam- 
menhangen,  ihre  Gliederung  und  Form  sind  undeutlich;  die  Knochen 
sind  durch  spathige  Masse  entstellt.  Es  folgen  nun  nach  riickwarts  fiinf 
gleichgestaltete,  deutlich  von  einander  abgegrenzte  Wirbel,  dann  kommt 
(der  VII  in  der  Reihe)  ein  von  diesen  etwas  verschieden  aussehender, 
weil  anders  gestellte  Wirbel  der  den  abschluss  des  Halses  bildet;  der 
unter  letzterem  befindliche  Wirbel  (der  achte,  [in  reality  the  ninth]) 
besitzt  bereits  eine  grossere  Rippe,  so  dass  mit  ihm  die  Reihe  der  Brust- 
wirbel  zu  beginnen  ist." 

Atlas  and  axis,  PI.  XLI,  Figs.  3—5.  The  atlas  is  coossified  with  the 
axis  for  the  most  part  in  the  adult  specimen,  though  leaving  a  distinct 
sutural  line  of  division  in  the  more  immature  specimen.  In  the  younger 
specimen,  the  coossification  is  less  complete,  and  the  axial  intercentrum 
is  also  apparent,  though  indistinguishable  in  the  older  specimen.  The 
atlas  is  composed  of  the  usual  number  of  parts,  though  the  centrum,  or 
odontoid  must  be  small.  The  intercentrum  forms  the  lower  third  or 
more  of  the  cup;  it  is  deeply  and  smoothly  concave,  with  a  sharp  cotylar 
rim,  which  is  nearly  semicircular  in  outline.  Its  upper  border  in  front 
has  three  parts:  the  middle  one,  concave  in  outline,  joins  the  odontoid; 
the  lateral  borders,  oblique  in  position,  join  the  bodies  of  the  neura- 
pophyses.  The  posterior  surface  is  probably  flat,  or  but  slightly  concave; 
the  sutural  line  with  the  axial  intercentrum  is  nearly  parallel  to  the  rim, 
and  the  width  is  slight,  though  a  little  greater  on  the  ventral  side,  where 
the  under  border  slopes  somewhat  ventrad  toward  the  axial  intercentrum. 

The  bodies  of  the  lateral  pieces,  or  neurapophyses,  of  the  atlas  com- 
plete the  rim  of  the  cup,  each  forming  a  little  less  than  one-third  of  the 
circumference.  Their  lower  border  unites  with  the  atlantal  intercentrum; 
the  inner,  lower  border,  joins  the  odontoid;  while  the  inner,  upper  bor- 
der, thinner  and  less  in  extent,  unites  with  its  mate  in  the  middle.  The 
dorsal  processes  or  arches  are  slender,  somewhat  oblique,  and  but  slightly 
dilated  at  the  distal  extremity,  which  appears  to  be  free.  They  apparently 
curve  backward,  to  be  applied  throughout  the  whole  of  their  extent,  to 
the  thin  neural  border  of  the  axis.  The  bottom  of  the  cup  is  formed  by 
the  odontoid.  Its  anterior  surface  has  three  convex  borders  of  nearly 
equal  extent,  ending  more  acutely  above.  How  deep  or  thin  this  bone  is 
cannot  be  said,  and  it  is  not  impossible  that  the  surface  appearing  in  the 
cup  is  really  the  anterior  face  of  the  body  of  the  axis,  the  odontoid  being 
obsolete.     The  inner  ends  of  the  lateral  pieces  are  thin,  and  it  is  impos- 

*Correspondenzblatt  des  Naturw.  Ver.  in  Regensburg,  38  Jahrg.,  1884,  p.  151. 


On  the  Osteology  of  Nyctosaurus.  131 

sible  to  say  whether  the  odontoid  appears  on  the  floor  of  the  neural 
canal  or  not. 

The  axial  intercentrum  is  a  large,  wedge-shaped  piece  intervening 
between  the  atlantal  intercentrum  and  the  body  of  the  axis.  It  is  scarcely 
keeled  in  the  middle  below  and  reaches  as  high  on  the  sides  as  does  the 
atlantal  intercentrum. 

The  body  of  the  axis  is  short  and  much  expanded  posteriorly.  Its 
ball  is  small  and  widened  transversely.  Below  the  ball  the  body  is 
expanded  into  a  very  large,  flaring  rim,  inclosing  a  deep  concavity, 
having  a  broad  articular  surface  transversely.  This  surface  evidently 
corresponds  to  the  united  postexapophyses  of  the  later  vertebrae  —  the 
"posterior  parapophyses "  of  Owen  and  Plieninger.  Nothing  quite  simi- 
lar to  this  structure  seems  to  have  been  observed  in  any  of  the  European 
pterodactyls,  though  an  axis  figured  by  Owen,*  as  also  Seeley,  seems  to 
approach  this  structure.  Nor  do  I  find  a  corresponding  adaptation  of 
structure  in  any  of  the  following  vertebras. 

The  arch  of  the  axis  is  broad  and  relatively  high.  The  neural  rim  in 
front,  to  which  are  applied  the  dorsal  neurapophyses  of  the  atlas,  is  thin, 
forming  a  heart-shaped  opening.  The  spine  is  broad,  low  in  front,  where 
there  is  a  thin  margin,  for  a  short  distance,  and  is  highest  behind.  The 
sloping  border  is  thickened,  the  posterior  border  thin.  Below,  on  each 
side,  there  projects  backward  a  strong  process,  on  the  under  side  of  which, 
before  its  termination,  is  the  small,  oval  zygapophysis. 

In  the  figures  given  in  PI.  XLI,  I  have  partially  restored  the  axis  and 
atlas  after  two  specimens,  both  complete,  but  compressed  in  different 
ways.     The  length  of  the  atlanto-  axis  is  14  mm. 

Plieningerf*  describes  the  atlas  in  Pterodactylus  kochii  as  consisting  of 
a  "ziemlich  massiven  Korper,  sowie  aus  einem  Nervenrohr  umschlies- 
senden  Bogenpaar,  welches  aussen  und  oben  jederseits  einen  Fortsatz 
tragt,  der  wohl  zur  Anheftung  von  Muskeln  diente."  He  also  identifies 
the  bone  considered  by  FraasJ  as  a  "  Schlundring  "  as  the  atlas.  From 
the  description  and  figure  it  would  seem  that  the  atlas  of  Pterodactylus 
is  of  a  very  different  structure  from  that  in  Nyctosaurus  and  Pteranodon. 
(I  have  seen  the  united  axis  and  atlas  in  a  species  of  the  latter  genus; 
they  resemble  the  same  bones  in  Nyctosaurus.} 

Third — seventh  cervical  vertebra,  PI.  XLIII,  Figs.  7-8.  The  cervical 
vertebra;  were  lying  close  together  between  the  back  of  the  skull  and  the 
top  of  the  thorax,  but  they  were  dislocated  and  disassociated,  so  that 
nothing  can  be  told  of  their  sequence  from  their  position.     Three  are 

*  Brit.  Fos.  Rept.  iv.  PI.  viii,  fig.  2. 
tPaleontographica,  igoi,  p.  17. 
%  Paleontographica,  xxv,  PI.  xxii  g 


132  Field  Columbian  Museum — Geology,  Vol.  II. 

lying  upon  their  ventral  surface,  that  is,  compressed  dorso-ventrally,  and 
two  were  more  or  less  crushed  laterally  or  obliquely.  There  is  less 
difference  in  the  lengths  of  the  five  following  the  axis  than  is  the  case  in 
Pteranodon ;  I  am  therefore  somewhat  in  doubt  as  to  the  precise  position 
of  some  of  them.  Those  that  are  depressed  have  the  under  surface 
irregularly  plane  or  concave,  with  the  lateral  margins  rounded  and 
concave,  formed  by  the  ridge  which  reaches  from  the  anterior  zygapo- 
physis  and  exapophysis  on  each  side  to  the  corresponding  posterior 
exapophysis.  At  the  front  margin  there  is  an  oval  fossa,  or  depression, 
on  each  side,  separated  by  a  convex  surface;  this  convexity  seems  often 
to  be  produced  into  a  distinct  hypapophysis  in  the  European  pterodactyls. 
In  a  previous  paper  I  stated  that  the  exapophyses  are  non-articular  in  this 
genus.  This  statement,  after  a  more  careful  examination  of  the  speci- 
mens removed  from  the  matrix,  I  know  to  be  erroneous,  at  least  so  far 
as  the  processes  of  the  posterior  vertebrae  are  concerned.  Owen  has 
identified  these  processes  with  the  parapophyses,  and  Plieninger  prefers 
to  adopt  this  name  for  them.  As  will  be  seen  by  an  inspection  of  Fig. 
7,  PI.  XLIII,  the  true  parapophysis — that  is  the  process  for  the  articulation 
of  the  head  of  the  rib,  for  which  the  term  was  originally  introduced  by 
Owen,  and  in  which  sense  it  is  now  used — is  always  situated  at  the  anterior 
end  of  the  vertebra,  close  to  the  rim  of  the  cup.  This  process  bears  on 
its  anterior  face,  close  to  the  rim  of  the  cup,  a  convex,  articular  surface 
for  union  with  the  corresponding  concave  surface  of  the  "  posterior 
parapophyses "  of  the  preceding  vertebra.  One  might  with  as 
much  propriety  call  these  posterior  prominent  articular  processes  the 
diapophyses,  or  posterior  inferior  zygapophyses,  as  "  posterior  para- 
pophyses." There  is  no  such  thing  as  a  posterior  parapophysis,  nor  can 
there  be.  Nor  could  these  posterior  "parapophyses"  ever  have  arisen 
as  processes  for  rib  articulation.  They  are  very  characteristic  of  the 
pterodactyl  vertebrae,  taking  the  place  of  the  lateral  or  double  articula- 
tion of  the  cryptodire  testudinate  cervical  vertebrae.  I  have  given  these 
articulations  a  distinctive  name  of  exapophyses  in  order  to  save  much 
circumlocution  in  their  description;  in  any  event  they  should  not  be 
called  "parapophyses,"  since  they  have  nothing  to  do  with  these  processes, 
either  morphologically  or  functionally. 

The  cup  and  ball  are  widened  transversely;  in  the  depressed  specimens 
very  much  so,  and  this  is  not  due  to  their  crushing,  since  those  lying  upon 
their  sides,  though  mutilated,  still  preserve  evidence  of  a  lateral  elonga- 
tion of  the  articular  surface.  The  convexity  of  the  ball  is  marked  dorso- 
ventrally,  more  so  near  the  neural  side.  The  posterior  border  between  the 
exapophyses  is  thin  and  concave,  nearly  concealing  the  ball,  when  seen 
from  below.     The  anterior  zygapophyses  project  much  in  front  of  the  cup; 


On  the  Osteology  of  Nyctosaurus.  133 

they  are  widely  separated  from  each  other.  A  ridge  extends  downward 
and  posteriorly  from  the  outer  side  of  the  zygapophysial  process  to  the 
outer  side  of  the  convex  exapophysis  or  parapophysis.  I  find  no  foramen 
inclosed  between  these  processes,  and  can  see  no  vestige  of  a  cervical 
rib,  such  as  is  described  in  certain  European  pterodactyls.  The  posterior 
zygapophyses  are  concave  and  oblique,  and  above  them,  there  is  a  more 
or  less  prominent  process,  a  sort  of  "  metapophysis."  They  do  not  extend 
as  far  back  as  the  ball,  leaving  a  wide  space  between  and  back  of  them  in 
which  the  floor  of  the  neural  canal  is  visible.  The  laminae  are  broad,  thin, 
and  roof-like,  meeting  in  the  middle  and  forming  a  very  thin,  neural 
spine.  The  length  of  the  base  of  this  spine  varies  not  a  little  in  the 
different  vertebrae,  from  twelve  to  sixteen  millimeters.  In  only  one 
vertebra  is  there  a  long  spine,  the  one  figured  in  PI.  XLI V,  Fig.  1 7,  which  I 
take  to  be  the  seventh  cervical.  In  the  others,  the  free,  thin  border  slopes 
slightly  upward  and  forward,  forming  a  rounded  spine  but  a  few  milli- 
meters in  height. 

Eighth  cervical  vertebra.  Pl.XLIII,  Fig.  8.  The  eighth  vertebra,  which, 
as  already  explained,  is  a  real  cervical  and  not  a  dorsal,  was  lying  close  to 
the  first  notarial  vertebra,  and  near  the  presternal  process  of  the  sacrum. 
It  has  been  so  much  compressed  that  all  of  its  characters  cannot  be  made 
out  with  clearness.  A  figure  of  it  is  given  as  it  lay  in  the  matrix.  It 
differs  greatly  from  the  vertebra  preceding  it  in  the  shortness  of  its 
centrum,  the  character  of  its  spine,  and  in  the  presence  of  diapophy- 
ses.  The  ball  is  transversely  widened,  and  has,  at  each  extremity, 
a  large,  concave,  articular  exapophysis.  The  post-zygapophyses  are 
situated  much  posteriorly  to  the  ball,  differing  therein  remarkably  from 
those  of  the  preceding  vertebrae.  The  spine  above  the  zygapophyses  is 
very  short  and  thick;  seen  from  behind,  it  is  concave,  and  ends  obtusely 
nearly  over  the  zygapophyses.  On  each  lateral  expansion,  near  the  upper 
extremity,  there  is  an  oval,  rounded,  smooth  surface,  forming  a  sort  of 
process  corresponding  to  the  "  metapophyses  "  of  the  earlier  vertebrae. 
The  front  border  of  the  spine  is  concave  in  outline,  and  is  rounded. 
There  is  a  rather  slender  and  moderately  long  diapophysis,  springing 
high  up  on  the  arch.  In  the  specimen  it  has  been  compressed  against 
the  vertebra,  but  seems  to  end  in  an  articular  process.  On  the  under 
side  of  the  vertebra,  near  the  mutilated  diapophysis,  there  is  a  fragment 
of  a  rib,  more  slender  than  those  of  the  notarium,  which  probably  belongs 
with  this  vertebra.  In  the  much  confused  anterior  end  of  this  vertebra, 
there  is  a  small  process  on  each  side,  evidently  the  exapophysis,  which  may 
also  have  served  for  the  articulation  of  the  head  of  the  rib;  if  so,  how- 
ever, the  head  must  have  been  small.  In  the  specimens  of  the  Pteranodon 
vertebrae  already  described,  this  parapophysis  seems  either  rudimentary  or 


134  Field  Columbian  Museum — Geology,  Vol.  II. 

wanting.  I  suspect  that  the  rib  was  single-headed  here.  Because  of  the 
small  size  of  this  rib,  the  large  size  of  the  exapophyses,  and  the  very  free 
union  of  the  vertebra,  as  also  because  of  the  position  of  the  notarium  in 
the  specimen,  apparently  in  articulation  with  the  first  tubercle  of  the 
sternum,  I  feel  confident  that  this  vertebra  does  not  articulate  with 
the  sternum,  and  that  it  is  a  cervical. 

Plieninger,  1.  c,  considers  the  eighth  shortened  vertebra  in  Ptero- 
dactylus  as  the  first  dorsal,  because  it  bears  a  diapophysis.  No  rib  was 
preserved  in  his  specimen,  and  he  does  not  state  whether  there  is-  a 
parapophysial  process  for  the  rib.  If  a  rib  was  present,  it  was  doubtless 
small,  since  the  next  three  pairs  of  ribs  are  found  in  place,  and  are 
"  besonders  kraftig."  The  next  three  or  four  pairs  are  also  strong.  The 
posterior  ribs  are  slender. 

Dorsal  vertebra.  PI.  XLI,  Fig.  i;  PI.  XLIII,  Fig.  7.  The  three  firmly 
united  vertebra?  of  the  notarium,  which  are  visible,  lie  with  their  ventral 
side  uppermost,  directed  a  little  obliquely  toward  the  left  side,  and  are 
partly  concealed  beneath  the  sternum.  The  front  end  lies  about  ten 
millimeters  back  of  the  front  end  of  the  presternal  process  of  the  sternum. 
The  first  two  centra  are  visible  nearly  wholly,  the  third  only  in  part.  The 
centra  are  flat  below,  concave  on  the  lateral  margins.  The  first  has  a 
concave  cup  margin,  and  on  each  side  a  stout  parapophysis  is  continued 
into  a  strong  rib,  without  clear  indications  of  sutural  union.  This  ver- 
tebra in  the  Kansas  University  specimen  has  the  ribs  free,  and  it  was 
itself  separable  from  the  following  centrum  through  its  suture;  it  is 
figured  in  PI.  XLIII,  Fig.  7,  and  has  already  been  described.  The 
parapophysis  of  the  second  notarial  vertebra  seems  to  be  given  off  some- 
what further  back,  and  there  are  indications  of  its  sutural  union  with  the 
rib  about  seven  millimeters  from  the  body.  The  rib  is  four  millimeters  in 
width  beyond  its  proximal  part,  and  a  length  of  about  thirty  millimeters 
was  preserved.  A  specimen  of  a  notarial  rib,  probably  the  first,  preserved 
with  the  Kansas  University  specimen,  has  a  length  of  forty-five  millimeters 
and  a  width  of  five.  The  corresponding  rib  in  this  specimen  must  have 
been  not  less  than  fifty  millimeters  in  length,  and  probably  about  sixty. 
Whether  the  third  vertebra  bears  similar  anchylosed  ribs  in  this  specimen 
cannot  be  said,  as  they  are  covered  by  the  sternum,  but  since  the  third 
vertebra  in  the  Kansas  University  specimen  has  such,  it  is  undoubtedly 
also  the  case  in  this.  The  end  of  a  flattened  rib,  about  twenty-five 
millimeters  in  length  and  three  or  four  in  width,  is  lying  by  the  articular 
margin  of  the  sternum,  and  may  belong  to  this  vertebra. 

Lying  in  the  axis  of  the  notarium,  a  convex  rim  of  a  dorsal  vertebra 
has  partly  protruded  through  the  thin  sternum.  This  vertebra  is  doubt- 
less either  in  direct  articulation  with  its  preceding  vertebra,  or  but  very 


On  the  Osteology  of  Nyctosaurus.  135 

slightly  removed.  The  length  of  the  series  is  about  fifty  millimeters, 
showing  that  five  vertebrae  are  associated  in  it,  and  that  the  protruding 
one  is  the  fifth.  Whether  the  fourth  and  fifth  are  both  suturally  united 
in  the  notarium  cannot  be  said,  but  in  all  probability  the  fifth  at  least  is 
free,  since  its  convexity  shows  it  to  be  of  the  nature  of  the  following  ones, 
and  because  one  of  the  small  posterior  ribs  seems  to  have  been  articulated 
with  it.  The  sixth,  seventh,  eighth,  and  ninth  vertebrae  are  nearly  in 
relation  with  each  other,  behind  the  sternum,  lying  upon  their  dorsal 
side,  but  are  pushed  somewhat  to  the  left.  They  are  cylindrical  in  cross- 
section,  with  smooth,  evenly  concave  sides  and  inferior  border,  with  a 
deep  cup  and  a  prominent  ball.  They  are  a  little  longer  than  broad,  of 
nearly  equal  length,  though  a  little  more  slender  posteriorly.  The  ante- 
rior zygapophyses  extend  in  front  of  the  cup.  The  elongated  and  slender 
diapophyses  arise  high  up  on  the  arch  from  near  the  anterior  part  of  the 
vertebra,  and  are  directed  horizontally  outward.  These  vertebra?  are  quite 
similar  to  those  of  Pteranodon,  and  are  doubtless  quite  like  that  figured 
by  Seeley  in  his  Dragons  of  the  Air,  p.  86,  Fig.  26.  The  last  dorsal  (or 
first  sacral)  (PI.  XLI,  Fig.  1,  dv),  the  tenth  back  of  the  neck,  is  flat  on  its 
inferior  surface,  and  its  transverse  process  I  think  arises  from  the  centrum 
as  in  Pteranodon.  It  is  firmly  united  with  the  sacrum  by  suture  in  both 
genera,  and  is  quite  as  properly  counted  with  the  sacrum  as  with  the 
dorsal  or  lumbar  vertebrae.  It  is  probable  that  its  transverse  process 
unites  with,  or  reaches  to,  the  anterior  projection  of  the  ilium,  as  seems 
also  to  be  the  case  in  Pteranodon. 

The  position  in  which  the  skeleton  is  lying  indicates  that  the  right 
coraco-scapula  and  the  pelvis  are  in  the  positions  in  which  they  were  as 
regards  each  other  while  yet  held  together  by  the  ligaments.  The  right 
arm,  falling  across  the  abdomen,  has  caused  a  slight  dislocation  of  the 
dorsal  vertebrae,  the  notarium  held  by  the  ribs  has  been  turned  somewhat 
obliquely,  and  the  sternum  has  settled  down  a  little  to  the  left.  The 
ends  of  the  scapulae,  however,  are  nearly  in  the  relative  position  to  each 
other  which  they  must  have  held  during  life,  and  the  axis  of  the  sacrum 
is  in  line  nearly  with  the  presternum. 

Now,  by  bringing  all  the  vertebrae  back  into  a  straight  line,  the  ten 
vertebrae  fill  the  entire  space  between  the  neck  and  the  true  sacrum, 
proving  almost  incontestably  that  there  were  neither  more  nor  less  than 
ten,  a  number  found  in  no  other  reptiles  except  the  turtles  and  Pareia- 
saurus;  indeed,  if  we  call  the  last  a  sacral,  then  there  are  fewer  presacral 
vertebrae  in  Nyctosaurus  than  in  any  other  known  reptile. 

The  sacrum  proper,  as  described  below,  is  composed  of  six  vertebrae, 
the  lines  of  sutural  union  of  which  are  clearly  visible  in  the  specimen. 

Four  caudal  vertebrae  are  preserved,  lying  close  to  the  proximal  end 


136  Field  Columbian  Museum — Geology,  Vol.  II. 

of  the  left  femur.  The  largest  of  these  (PL  XLIII,  Fig.  11),  that  evidently 
immediately  succeeding  the  sacrum,  is  flat  at  each  end,  and  has  neither 
distinct  processes  nor  zygapophyses,  and  only  a  small,  low  spine  on 
the  posterior  part;  its  width  posteriorly  is  much  less  than  that  anteriorly. 
The  other  three  vertebrae  are  in  a  series,  slightly  separated  from  each 
other,  and  are  mere  nodules  of  bone,  without  processes  of  any  kind, 
about  four  millimeters  in  length  by  three  in  width;  the  last  one  ends  in 
a  conical  point.  From  the  tapering  of  the  first,  and  the  association  of 
the  last  three  close  by  the  side  of  the  femur  it  seems  very  probable  that 
the  tail  was  short  and  slender. 

measurements  of  vertebrae. 

Length,        Width,         Expanse, 
mm.  mm.  mm. 

Atlanto-axis 14  

Third  cervical 24  

Seventh  cervical 21  

Eighth  cervical  (about) 9  

First  dorsal 9 

Second  dorsal 10 

Third  dorsal 10 

Length  of  first  five  dorsals  (about) 53 

Sixth  dorsal 9 

Seventh  dorsal . 9 

Eighth  dorsal . 9 

Ninth  dorsal 9 

Lumbar  (tenth) 10 

First  true  sacral 9 

Second  sacral 9 

Third  sacral 7.5 

Fourth  sacral 7 

Fifth  sacral 6 

Sixth  sacral 6 

First  caudal,  or  caudo-sacral 7 

Distal  caudals 4,  4,  4, 

RIBS. 

Thoracic.  PL  XLI,  Fig.  1,  r,r.  There  are  apparently  four  pairs  of 
stout  ribs  arising  from  the  first  four  dorsal  vertebrae,  the  first  three  of 
which,  at  least,  are  anchylosed  to  the  centrum  in  the  adult  animal.  They 
were  doubtless  all  attached  to  the  four  tubercles  on  each  side  of  the 
sternum. 

Beginning  with  the  fifth  dorsal,  the  ribs  are  single-headed,  and  are 
very  slender  and  delicate.  Four  pairs  are  discernible  in  the  specimen, 
and  a  fifth  seems  to  be  indicated  by  a  fragment.  The  largest  of  these, 
that  apparently  belonging  with  the  fifth  dorsal,  is  gently  curved.     It  meas- 


II 



II 



II 



8 

3i 

8 

30 

7-5 

29 

8 



9 

32 

7-5 

35 

7-5 

37 

7-5 

32 

7 

28 

6.5 

21 

6.5 

15 

10(8) 



3.3.3 



On  the  Osteology  of  Nyctosaurus.  137 

ures  about  75  ram.  in  length,  2  across  its  somewhat  expanded  head,  .8 
across  the  shaft  a  little  beyond  the  capitular  thickening,  and  but  .4  near  its 
distal  extremity.  The  sixth  vertebra  has  its  rib  on  the  left  side  in  relation 
with  the  extremity  of  the  diapophysis;  it  is  a  little  shorter,  .75  in  width 
near  its  proximal  extremity,  and  .3  distally.  The  seventh  also  has  a  rib  in 
relation  with  the  left  diaphophysis;  it  is  yet  shorter,  and  nearly  straight; 
measures  .6  in  width  proximally,  and  .2  distally.  The  next  rib  is  straight, 
and  yet  more  slender,  and  shorter.  The  tenth  vertebra,  that  connected 
with  the  sacrum,  I  do  not  think  bore  a  free  rib. 

In  a  former  paper  I  stated  my  belief  that  the  slender,  posterior,  single- 
headed  ribs  did  not  inclose  the  abdominal  cavity,  but  were  directed  more 
or  less  outwardly  in  the  patagial  membrane.  In  support  of  this  belief  it 
is  seen  that  all  these  ribs  are  remarkably  slender,  and  but  slightly  if  at  all 
curved.  Their  free  and  loose  connection  with  the  vertebrae,  and  their 
delicacy  prevented  them  from  being  of  use  as  a  support  to  the  abdominal 
contents;  certainly  not  if  the  animal  walked  in  a  quadrupedal  position. 
Furthermore,  if  they  extended  in  the  walls  of  the  abdomen,  the  abdomen 
must  have  been  exceedingly  voluminous,  and  widely  unprotected  in  front. 

A  better  support  for  my  contention  is  afforded  by  the  position  of  the 
various  bones  in  this  specimen  as  they  are  preserved.  All  these  ribs  lie 
directed  outwardly  or  obliquely  backward,  and  none  of  them  are  mutilated 
or  broken  in  the  least,  save  as  may  have  happened  in  the  preparation  of 
the  specimen.  The  right  arm  lies  obliquely  across  the  abdomen;  it  was 
evidently  sustained  by  the  soft  parts  until  after  the  ligaments  connecting 
the  forearm  bones  had  partly  decomposed,  since  these  two  bones  and  the 
carpals  only  are  slightly  disassociated  from  the  remainder  of  the  wing 
bones.  The  radius  and  ulna  fell  to  the  back  part  of  the  abdominal 
cavity  while  yet  the  pelvis  was  held  together,  permitting  the  left  innomi- 
nate bone  to  fall  outward  over  the  end  of  the  ulna  and  carpal.  Further- 
more, the  ventral  ribs  have  fallen  upon  the  radius.  Now,  under  these 
conditions,  had  the  ribs  curved  forward  in  the  abdominal  walls  to  meet 
the  ventral  ribs,  they  surely  would  have  been  entangled  and  doubled  up 
beneath  the  forearm.  But  this  is  not  at  all  the  case,  and  it  seems  highly 
improbable  that  the  fleshy  walls  of  the  abdomen  could  have  fallen  apart, 
and  spread  out  laterally  with  the  wing  folded  across  them.  From  all  of 
which  evidence,  I  believe  that  the  ribs  were  directed  laterally,  supporting 
the  patagial  membrane,  perhaps  as  in  Draco,  and  that  they  did  not  inclose 
the  abdominal  cavity. 

Further  evidence  of  the  same  tenor  is  furnished  by  the  type  specimen 
of  Rhamphorhynchus  phyllurus  Marsh,  which  I  have  recently  examined. 
In  this  specimen,  the  right  arm  had  also  fallen  across  the  abdomen,  while 
yet  having  the  patagial  membrane  attached  to  it.     Nevertheless,  the  very 


138  Field  Columbian  Museum — Geology,  Vol.  II. 

slender  ribs  are  spread  outwardly,  and  were  not  doubled  up  below  the 
wing  bones.  They  cannot  be  ventral  ribs,  since  these  are  large  and  broad 
in  this  species  of  Rhamphorhynchus,  according  to  Zittel. 

In  Pterodactylus  spectabilis,  as  figured  in  the  books,  a  number  of  very 
delicate  abdominal  ribs  are  shown,  as  depicted  by  Von  Meyer.  "  An  die 
unteren  Halfte  des  Rumpfes  kommen  fiinf  fadenformige  Abdominalrip- 
pen.  Sie  sind  fadenformige,  ohne  sich  gegen  die  Mitte  her  zu  verstarken, 
und  bei  ihre  Lange  und  diinnen  Beschaffenheit  etwas  verbogen.  Die  erste 
Rippe,  die  langste,  ergiebt  0.026."*  Is  it  possible  that  the  abdominal 
and  vertebral  ribs  have  been  confused  in  this  description? 

Ventral  ribs  or  parastemum.  PI.  XLI,  Fig.  2.  The  ventral  ribs  were, 
for  the  most  part,  lying  in  position  nearly  contiguous  with  the  xiphisternal 
process.  There  appear  to  be  four  pairs,  the  first  three  lying  together  and 
united.  The  first  pair  is  somewhat  uncertainly  shown,  broken  on  the  left 
side  and  partly  concealed  on  the  right  below  the  border  of  the  sternum. 
The  second  pair  is  very  distinct.  They  are  somewhat  V-shaped,  co-ossified 
and  thickened  in  the  middle,  and  terminating  outwardly  in  a  slender 
point.  The  third  pair  was  in  position,  co-ossified  with  the  margins  of  the 
second  pair,  but  not  united  in  the  middle.  Another  pair  is  seen  by  the  right 
side  of  the  tenth  vertebra,  partly  beneath  the  ulna;  their  whole  form  can- 
not be  made  out,  but  they  are  wider  and  longer,  apparently,  than  the  third 
pair,  to  which  they  could  have  had  no  ossific  union.  These  ribs  are  all 
thin.  In  the  restoration  it  seems  evident  that  the  last  pair  of  these  ribs 
would, approach,  if  not  actually  meet  at  their  ends,  the  anterior  ends  of 
the  prepubic  processes.  I  am  very  much  inclined  to  believe  that  the 
prepubis  is  really  not  a  part  of  the  pelvis,  but  rather  a  part  of  the  para- 
sternal ossifications. 

One  of  the  best  descriptions  extant  of  the  ribs  of  pterodactyls  is  that 
of  von  Ammon  (op.  ct.): 

"  Die  hintersten  dreizehnte  Rippe  stellt  einen  zarten  Knochenstreifen 
vor.  Das  untere  Ende  der  Rippen  ist  verdickt  und  bildet  ein  kleines 
Gelenkkopfchen,  an  welchem  der  obertste  Theil  einer  Gurtelrippe  der 
Bauchwand  befestigt  ist.  .  .  .  Durch  ihre  Verbindungen  [d.  h.  der 
Abdominalrippen]  mit  den  oberen  Rippen  bestehen  also  vollstandige 
Giirtel  in  der  Bauchwand.  Es  schliessen  sich  immer  zwei  Bauchrippen  zu 
einem  formlichen  Halbkreis  zusammen.  Am  Vereiningungspunkte  ist 
eine  mediane  Verdickung  vorhanden,  die  eine  nach  unten  Spitz  auslau- 
fendes  langes  Kopfchen  bildet."  The  ventral  ribs  of  this  pterodactyl 
{Rhamphorhynchus  longicaudatus)  are  very  thin  and  simple,  in  contrast 
with  the  broad  ventral  ribs  of  the  larger  forms  of  Rhamphorhynchus, 
according  to  Zittel. 

*Paleontographica,  vol.  x,  p.  4,  1868. 


On  the  Osteology  of  Nvctosaurus.  139 

Owen*  says  that  '■  the  ribs  of  Dimorphodon  acquire  a  characteristic 
tenuity  beyond  the  sixth  pair,"  and  Seeley  mentions  the  fact  that  the 
posterior  ribs  of  the  pterodactyls  are  slender.  In  current  restorations  of 
the  pterodactyls,  the  posterior  ribs  are  often  shown  as  long  and  strong 
bones,  inclosing  a  large  and  deep  abdomen,  the  outlet  of  which  must 
have  been  through  the  narrow  pelvis.  It  has  been  suspected  that  there 
are  sternal  ribs  intervening  between  the  vertebral  ribs  and  the  sternum, 
but  there  is  no  evidence  of  such  in  the  present  specimen. 

PECTORAL  GIRDLE  AND  EXTREMITY. 

So  far  as  is  definitely  known,  the  pectoral  girdle  comprises  the  ster- 
num, coracoid  and  scapula  only.  No  clavicles  (unless  the  ossification 
hereinafter  described  is  a  clavicle),  inter-clavicle,  epicoracoids,  or  precora- 
coids,  even,  are  known.  Furthermore,  the  bones  present  are  so  strangely 
modified  that  they  present  very  little  resemblance  to  the  same  elements 
in  other  reptiles,  agreeing  rather  better  with  those  of  birds,  an  agreement, 
however,  that  I  believe  to  be  homoplastic  in  nature. 

Sternum.  PI.  XLII,  Fig.  1.  The  sternum  is  a  broad  and  thin  bone, 
with  a  stout  anterior  projection,  and  a  thin,  spatulate  xiphisternal  process 
posteriorly.  The  presternal  process  is  narrowed  and  rounded  on  the 
under  surface,  and  may  have  projected  somewhat  ventrad.  The  saddle- 
shaped  articular  surfaces  for  the  coracoids  look  dorsad  and  laterad.  The 
anterior  borders  at  the  sides  of  the  presternal  projection  are  thickened, 
concave  slightly  in  outline  on  the  inner  part,  straight  and  more  oblique 
on  the  outer  ends.  The  lateral  margins  are  thin,  and  are  nearly  parallel 
with  the  median  axis  of  the  bone.  These  borders  have  three  emargina- 
tions,  separated  by  four  rounded  projections,  the  anterior  one  longer  and 
thicker  than  the  others,  which  are  thin  and  small.  The  posterior  border 
is  convex  on  either  side,  ending  in  a  short  and  deep  concavity  at  each 
side  of  the  flat  xiphisternal  process.  This  process  is  spatulate,  with  the 
distal  end  rounded  or  very  slightly  emarginate,  and  doubless  gave  attach- 
ment to  the  series  of  abdominal  ribs,  which  lie  in  the  specimen  nearly 
in  connection  with  it.  The  sternum  is  somewhat  thickened  in  the  middle 
anteriorly,  or  back  of  the  base  of  the  anterior  process.  On  the  sides  and 
behind  the  bone  is  very  thin,  almost  paper-like;  this  thinner  part  in  the 
specimen  shows  numerous  small  crinkly  fractures,  doubtless  caused  by  the 
flattening  of  the  concave  bone;  similar  crinkles  are  visible  in  the  thin 
prepubic  bones.  The  sternum  lies  nearly  in  its  normal  position  in  the 
skeleton.  In  falling  backward  it  has  been  displaced  a  little  obliquely  to 
the  long  axis  of  the  body,  as  have  the  dorsal  vertebrae,  perhaps  caused  by 

*  Paleontographica  Soc,  1869,  p.  69. 


140  Field  Columbian  Museum — Geology,  Vol.  II.  ' 

the  weight  of   the  right  arm   lying  across    the  body.     The  presternal 
process  extends  about  half  an  inch  in  front  of  the  notarium. 

measurements  of  sternum. 

mm. 

Length  in  middle 88 

Greatest  width,  across  attachments  of  first  rib 80 

Length  of  rib  margins 28 

Width  at  coracoidal  articulations 40 

Length  of  presternal  process  in  front  of  coracoids  — 16 

Width  of  xiphisternal  process 9 

Length  of  xiphisternal  process 11 

Coraco- scapula.  PI.  XLIII,  Fig.  6.  This  conjoined  element  is  a  mod- 
erately stout,  U-shaped  bone,  with  the  coracoid  branch  stouter  and  a  little 
longer  than  the  scapular.  The  distal  extremity  of  the  scapula  is  slightly 
expanded  and  flattened  spatulate;  the  shaft  is  flattened  and  somewhat 
constricted  in  width.  There  is  a  rounded  protuberance  on  the  outer  or 
upper  margin,  just  beyond  the  glenoid  rim,  for  the  attachment  of  muscles. 
This  process  appears  to  be  wanting  in  the  specimen  previously  described 
by  me  of  this  genus,  but  it  is  possible  its  absence  is  due  to  some 
postmortem  compression.  The  glenoid  articulation  is  deeply  concave 
from  above  downward,  convex  from  side  to  side,  and  is  bounded  both 
above  and  below  by  a  prominent  ridge,  that  on  the  inferior  border  being 
much  stronger  than  the  upper  one.  The  glenoid  surface  is  placed 
obliquely  to  the  shaft  of  the  bones,  doubtless  in  life  looking  outward 
and  somewhat  backward.  The  surface,  from  side  to  side,  is  narrower 
below  than  above.  A  line  indicating  the  sutural  union  of  the  two  bones 
passes  directly  through  the  middle  of  the  articular  surface  transversely. 
At  the  bottom  of  the  U  formed  by  the  conjoined  bones  there  is  a 
process,  rather  slender,  arising  from  the  inner  surface  of  the  scapula, 
and  reaching  to  the  inner  face  of  the  coracoid,  which  it  joins.  It  incloses 
a  small  foramen  between  it  and  the  coracoid,  back  of  and  below  the 
glenoid  surface.  A  precisely  similar  process  is  found  in  the  coraco- 
scapula  of  Pteranodon,  and  in  neither  genus  does  the  suture  dividing  the 
coracoid  from  the  scapula  cross  this  process;  it  is,  apparently  without 
doubt,  either  a  separate  ossification  joined  to  the  two  bones,  or  else  a 
process  from  the  scapula.  I  cannot  at  present  examine  the  under  sur- 
face of  this  scapula,  and  have  none  of  Pteranodon  for  comparison.  In 
Nyctosaurus,  however,  the  process  seems  to  be  separated  from  the  scapula 
throughout  a  large  part  of  its  extent.  If  it  really  belongs  with  the  scapula, 
the  inclosed  foramen  cannot  be  the  usual  supracoracoid  foramen  of  the 
reptilian  coracoid. 

A  similar  foramen,  though  of  larger  size,  is  shown  by  Owen  in  the 
coraco-scapula  of  Ornithocheirus  sedgwicki  (Paleontograph.,   1857),  which 


On  the  Osteology  of  Nyctosaurus.   '  141 

he  calls  doubtfully  a  pneumatic  foramen.  Whether  the  part  is  an  acro- 
mion process  of  the  scapula,  or  possibly  a  vestigial  clavicle,  must  be  left 
for  future  research. 

The  coracoid  has  a  flattened  shaft,  oval  in  cross-section  near  its  middle, 
and  flattened  at  either  extremity.  The  sternal  articular  surface  is  convex 
in  its  greater  diameter,  gently  concave  in  the  opposite  direction.  Near 
the  outer  extremity  of  the  shaft,  on  the  inferior  border,  there  is  a  strong 
process,  gradually  arising  f-rom  the  shaft  but  with  a  deep  concavity  be- 
tween it  and  the  articular  rim.  A  small  sesamoid  ossicle  was  found 
lying  near  it.  The  shaft  at  its  middle  is  narrowed  and  smooth;  it  seems 
to  lack  the  strong  muscular  rugosity  on  the  external  part  which  occurs  in 
the  Pteranodon  coracoid;  the  process  on  the  outer  inferior  border  is  also 
larger  than  in  Pteranodon.  It  will  be  observed  also  in  the  figure  that 
the  glenoid  articular  surface  does  not  extend  to  the  inferior  margin  of  the 
coracoid,  resembling  in  this  respect  somewhat  the  European  forms  of  this 
bone.  The  scapula  of  course  differs  markedly  from  that  of  Pteranodon 
in  the  non-articular  distal  end. 

measurements  of  coraco-scapula. 

mm. 

Extent  of  coraco-sternal  articulation 10 

Least  width  of  shaft,  below  middle  of  coracoid _  7 

Length  of  coracoid .; 55 

Dorso-ventral  diameter  of  glenoid  surface --  19 

Length  of  scapula 49 

Least  width  of  shaft  of  scapula 14 

Width  at  distal  extremity 16 

Humerus.  PI.  XLII,  Fig.  7.  The  humeri  both  lie  with  the  inner 
side  uppermost.  The  proximal  articular  surface  is  distinctly  saddle- 
shaped,  the  convexity  directed  from  behind  forward  and  inward.  The 
curve  of  the  concavity  is  greater  than  that  of  the  convexity  in  the  speci- 
men. The  ulnar  or  median  process  is  very  stout,  reaching  as  high 
as  the  articular  surface.  It  is  broad  above,  with  apparently  two  faces 
for  muscular  attachment,  separated  by  a  narrow,  free  space.  Its  rounded 
distal  border  sinks  into  the  surface  of  the  shaft  at  about  its  middle 
third.  The  deltoid,  radial,  or  lateral  process  is  very  large.  It  is  directed 
forward  and  a  little  downward,  its  lower  margin  uniting  with  the  shaft 
at  about  the  middle  third.  Both  upper  and  lower  borders  are  deeply 
concave,  the  upper  one  the  longer.  Its  distal  extremity  is  expanded, 
and  has  an  evenly  convex  border  from  above  downward.  Near  the 
upper  end  of  this  border,  on  the  inner  side,  there  is  a  small,  oval, 
oblique  surface,  looking  inward,  for  muscular  attachment;  and,  begin- 
ning near  the  middle  of  the  upper  border,  there  is  a  slender,  but  well- 


142  Field  Columbian  Museum — Geology,  Vol.  II. 

marked  ridge,  also  for  muscular  attachment,  traversing  the  anterior  face 
obliquely,  and  terminating  near  the  lower,  outer  angle  of  the  process. 
Fiirbringer  says  of  these  processes  in  the  pterosaurs:  "Proc.  lateralis  und 
Proc.  medialis,  namentlich  aber  der  erstere  sind  sehr  kraftig  entwickelt 
und  prominieren  insbesondere  proximal  so  stark,  dass  das  zwischen 
ihnen  befindliche  Caputhumeri  sogar  theilweise  gegen  sich  zuriicktreten 
kann;  dagegen  ist  —  sehr  im  Unterschiede  zu  den  meisten  Sauropsiden, 
namentlich  aber  den  Theromorphen  und  Dinosauriern  —  der  Proc.  later- 
alis wenig  in  die  Lange  entwickelt,  indem  er  gewohnlich  nur  das  proximal 
%  bis  y$  des  Humerus  einnimmt.  Diese  Konfigurationen  lassen  darauf 
schliessen,  dass  die  Mm.  supracoracoideus  (supracoracoscapularis,  scapulo- 
humeralis  posterior  und  subcoracoscapularis)  eine  relativ  hohe  Entfaltung 
besassen,  der  M.  pectoralis  dagegen  keine  so  abnorme  Starke  darbot, 
wie  es  von  vornherein  von  einem  fliegenden  Thiere  erwartet  werden 
konnte,  und  der  M.  deltoides  nur  mittelstark  entwickelt  war."* 

The  shaft  below  the  lateral  process  is  of  nearly  uniform  width.  A  little 
above  the  middle  of  each  bone,  on  the  inner  or  ventrolateral  side,  starting 
from  precisely  the  same  place,  and  lying  transversely,  there  is  a  slender 
bone,  less  than  a  millimeter  in  width,  and  about  twelve  millimeters  in 
length,  preserved.  I  do  not  know  what  it  is,  nor  whether  it  really 
belongs  in  this  position,  though  the  similarity  of  the  bone  on  the  two 
sides  suggests  that  it  does.  It  may  be  an  ossified  tendon.  .  .  Because 
of  the  position  in  which  both  humeri  are  lying,  the  distal  extremity 
has  been  transversely  compressed,  effacing  the  articular  surfaces  to  a  great 
extent.    There  seems  to  be  a  small  depression  on  the  inner  epicondyle. 

MEASUREMENTS  OF   HUMERUS.  mm. 

Length '. 87 

Least  width  of  shaft 5 

Least  width  of  lateral  process -  17 

Width  of  lateral  process  distally 25 

Width  of  humerus  through  lateral  process 42 

Width  of  median  process 5 

Ulna.  PI.  XLII,  Fig.  2.  The  bones  of  the  left  forearm  lie  nearly  in 
position,  and  in  contact  with  the  distal  end  of  the  humerus;  those  of  the 
right  side  have  been  slightly  separated,  the  radius  detached  and  removed 
proximally.  The  left  ulna  is  lying  nearly  upon  its  outer  side,  partly  over- 
lapping the  radius;  that  of  the  right  forearm  has  been  compressed  dorso- 
ventrally.  The  bone  is  slightly  expanded  at  the  extremities.  There  are 
two,  nearly  confluent,  articular  surfaces  at  the  proximal  end,  the  smaller, 
nearly  circular  one,  on  the  inner  side,  nearly  confluent  with  the  large,  less 

*Jenas.  Zeitschrift,  1900,  p.  363. 


On  the  Osteology  of  Nyctosaurus.  143 

deeply  concave  surface  on  the  inner  side.  Just  in  front  of  this,  near  the 
middle  of  the  bone,  transversely,  there  is  a  pneumatic  foramen  on  the 
flexor  side.  The  inner  side  of  the  bone,  at  this  extremity  is  expanded 
into  a  thin,  convex  process.  The  articulation  at.the  distal  extremity  can- 
not be  made  out,  as  it  is  largely  concealed  by  the  carpals.  The  shaft  is 
nearly  straight,  curved  forward  gently  at  the  distal  extremity. 

measurements. 

mm. 

Length 144 

Width  of  proximal  extremity - — 44 

Width  of  shaft -• •- 24 

Radius.  PI.  XLI,  Fig.  2,  PI.  I.  The  radius  is  a  more  slender  and 
slightly  shorter  bone  than  the  ulna.  On  the  left  side  it  lies  partly  con- 
cealed beneath  the  ulna  and  there  would  seem  to  have  been  no  pronation 
of  the  bone.  The  bone  is  more  slender  than  the  radius,  somewhat  concave 
along  its  inner  or  upper  border  as  it  lies  in  relation  with  the  ulna;  nearly 
straight  as  it  lies  compressed  from  above  downward.  The  bone  is  more 
expanded  distally  than  proximally.  The  proximal  articular  surface  is 
rounded  and  concave.  Lying  near  the  roughened  distal  surface  shown 
in  the  figure  there  was  a  small  sesamoid  bone. 

MEASUREMENTS   OF    RADIUS. 

mm. 

Length - 140 

Width  of  shaft  middle  third . 18 

Width  distal  extremity 24 

Carpals.  PI.  XLII,  Figs.  2,  edt  3,  PI.  XLIV,  Fig.  8.  The  two  chief 
carpals  of  the  left  wrist  are  in  relation  with  each  other  and  the  wing  meta- 
carpal, and  but  slightly  displaced  from  the  forearm  bones.  On  the  right 
side  they  are  separated,  and  the  proximal  one  is  partly  concealed  beneath 
the  ischium,  the  distal  one  having  its  proximal  surface  obliquely  exposed. 
In  the  figure  (PI.  XLIV,  Fig.  10),  the  one  shown  obliquely  is  that  of  the 
other  carpus  figured.  The  wing  metacarpal  of  the  left  side  (PI.  XLIV,  Fig. 
2),  lying  articulated  with  the  distal  carpal,  has  the  under  side  uppermost, 
from  which  it  would  appear  that  the  view  given  is  of  the  anterior  side  of 
the  carpus.  The  proximal  carpal  is  much  the  larger,  extending  on  the 
under  side  either  to  articulate  with  the  metacarpal,  or  nearly  so.  A  sub- 
angular  space  is  left  between  the  two  bones  on  the  radial  side,  for  the 
articulation  of  the  lateral  carpal  or  metacarpal  of  the  first  digit.  This 
latter  bone,  of  the  right  side,  is  shown  in  PI.  XLII,  Fig.  3.  It  is  a  small, 
elongate  bone,  with  an  articular  emargination  on  one  side,  which  I  had 
supposed  was  for  the  pteroid.  I  give,  also,  a  good  figure  of  this  bone 
of  Pteranodon,  copied    from  Cope    (Cretaceous   Vertebrata,    Plate   VII, 


144  Field  Columbian  Museum — Geology,  Vol.  II. 

Fig.  3).  It  resembles  that  of  Nyctosaurus,  though  having  a  less  elon- 
gated process  beyond  the  articular  lateral  emargination.  The  figures  of 
the  carpal  bones  of  Ornithocheirus  given  by  Seeley  (Ann.  Mag.  Nat.  Hist. 
Aug.  1870,  and  Dragons  of  the  Air,  p.  124)  closely  resemble  these  bones. 
Professor  Seeley  says  of  the  "  lateral  carpal  ":  "  It  is  a  flat,  oblong  bone, 
attached  to  the  inner  side  of  the  distal  carpal,  and,  instead  of  being  pro- 
longed distally  in  the  same  direction  as  the  other  metacarpal  bones,  is 
turned  round  and  directed  upward,  so  that  its  upper  edge  is  flush  with  the 
base  of  the  radius,  and  gives  attachment  to  the  pteroid."  I  had  supposed 
that  the  larger  end,  as  shown  in  the  present  figure,  fitted  into  the  interval 
between  the  two  carpals,  and  that  the  emargination  was  for  the  articulation 
of  the  rounded  head  of  the  pteroid,  though  perhaps  the  position  assigned 
to  it  by  Seeley  is  the  correct  one.  The  bone  is  thin  on  the  sides  shown  in 
the  figure,  so  that  the  articulation  of  the  pteroid  must  have  been  either  in 
the  emargination  or  with  the  broader  end.  Marsh  says*  that  it  "  stands 
nearly  at  right  angles  with  the  wrist,"  and  I  am  inclined  to  think  he  was 
right.  The  structure  of  these  wrist  bones  is  almost  identical  with  what  it 
is  in  Pteranodon. 

measurements  of. carpal  bones. 

mm. 

Length  of  articulated  carpus 15 

Greatest  diameter  of  distal  carpal 24 

Lesser  diameter  of  same 14 

Greatest  diameter  of  proximal  carpal 26 

Length  of  "lateral  carpal" 17 

Width  of  same 8 

Metacarpals.  The  first  metacarpal,  or  pteroid  (PI.  XLII,  Figs.  4,  5), 
is  an  elongated,  pointed,  styliform  bone,  with  an  enlarged  articular  car- 
pal extremity.  In  both  arms  this  bone  has  been  displaced,  though  so 
closely  associated  with  the  corresponding  extremity  that  the  position  is 
assured.  Its  articular  end  is  broad,  its  margin  nearly  at  right  angles  with 
the  long  axis  of  the  bone.  The  articular  surface  is  nearly  at  right  angles 
with  the  transverse  diameter,  in  life  nearly  circular  in  outline,  and  decid- 
edly convex.  It  is  separated  from  the  bone  by  a  slight  constriction. 
The  dorsal  border  of  the  bone  is  very  gently  concave  throughout,  and 
the  inferior  border  is  correspondingly  convex  for  the  greater  part  of  its 
extent.  The  pteroid  of  the  right  arm  is  lying  close  to  the  lateral  carpal, 
as  though  its  articular  surface  fitted  into  the  lateral  emargination  of  that 
bone  in  life.  Oscar  Fraas  was  the  first,  so  far  as  I  can  learn,  to  recognize 
the  real  nature  of  this  bone  as  belonging  to  the  first  digit,f  a  view  after- 
wards adopted  by  Marsh  and  Zittel.     . 

♦Amer.  Journ.  Sci.,  1882,  p.  255.  * 

fPaleontographica,  1878,  p.  170. 


On  the  Osteology  of  Nyctosaurus.  145 

measurements  of  pteroid. 

mm. 
Length 104 

Greatest  width  (at  proximal  end) 15 

Diameter  of  articular  surface 8 

The  next  three  metacarpals  are,  for  the  most  part,  wanting  in  this 
specimen,  a  single  complete  one  lying  near  the  distal  extremity  of  the 
right  wing  metacarpal  (PI.  XLII,  Fig.  6).  It  is  a  very  small,  splint- 
like and  slightly  curved,  pointed  bone,  measuring  about  twenty-four 
millimeters  in  length  by  two  in  greatest  width.  Its  resemblance  to  the 
corresponding  metacarpals  of  Pteranodon  is  so  great  that  the  whole 
structure  of  the  hand  is  doubtless  the  same  in  the  two  genera.  I  give 
herewith  a  diagrammatic  figure  of  these  parts  in. Pteranodon,  based  on  a 


^Y^ 


Fig.  2.    Metacarpals  of  Pteranodon  ingens. 

specimen  in  which  nearly  all  the  bones  were  present  and  in  position, 
some  of  the  terminal  phalanges  only  being  misplaced,  and  one  or  two  of 
the  fourth  finger  missing.  In  a  former  paper  I  stated  that  the  phalanges 
of  the  hand  were  of  two  kinds,  long  and  short.  Possibly  this  is  the  case 
in  some  of  the  smaller  species,  but  I  think  not.  I  doubt  not  that  the 
small  phalanges  there  described  were  from  the  foot,  and  had  become  dis- 
placed and  associated  with  the  hand  phalanges  in  the  specimen  described. 
In  the  specimen  of  Pteranodon  the  small  metacarpals  seemed  to  lie, 
not  as  they  are  diagrammatically  figured,  one  above  the  other,  but  more 
side  by  side.  The  second  metacarpal  is  continued,  as  already  stated  by 
Marsh,  to  the  carpus,  as  a  thin,  thread-like  bone.  It  was  not  continued 
along  the  dorsal  side  of  the  bone,  but  seems  to  pass  to  the  radial  side, 
where  it  belongs.  From  this  it  seems  also  probable  that  the  position  of 
all  three  bones  in  life  was  along  the  radial  dorsal  margin  of  the  fifth 
metacarpal. 

Both  of  the  wing  metacarpals  (PI.  XLIV,  Fig.  2)  lie  upon  the  dorsal 
surface,  a  position  in  which  they  are  seldom  found.  The  bone  is  much 
broader  at  the  base,  tapering  to  beyond  the  middle,  whence  the  shaft 
has  nearly  parallel  sides.  The  proximal  articular  surface  cannot  be 
made  out,  though  there  appears  to  be  a  division  into  two  facets.  The 
condyles,  as  in  Pteranodon,  are  placed  obliquely,  the  posterior  one  the 
larger. 


146  Field  Columbian  Museum — Geology,  Vol.  II. 


MEASUKEMENTS. 

mm. 

Length 224 

Width  at  proximal  end 18,  23 

Width  of  shaft  at  middle u,  12 

First  phalange  of  wing  finger.  PI.  XLIV,  Fig.  1.  The  first  phalange,  as 
usual,  lies  upon  the  side  in  both  wings.  As  in  Pteranodon,  it  is  the  long- 
est bone  of  the  body.  Its  under  margin  is  concave  throughout,  the  con- 
cavity greater  near  each  end.  The  proximal  expanded  extremity  has  a 
deep  articular  concavity,  extending  through  an  arc  of  about  one-third  of 
a  circle,  with  its  radius  directed  at  an  angle  about  45 °  with  the  long  axis. 
The  upper,  olecranon-like  projection  has  a  marked  emargination  of  the 
border  above,  between  which  and  the  proximal  end  the  convexity  is 
greater,  with  the  corresponding  deeper  concavity  of  the  under  border. 

There  are  two  articular  facets,  separated  by  a  median  ridge,  which 
fits  into  the  trochlear  depression  of  the  metacarpal.  The  posterior  sur- 
face extends  throughout  the  whole  length  of  the  arc,  while  that  on  the 
anterior  side  reaches  but  little  more  than  one  half  of  the  distance,  and 
its  upper  part  is  narrower  than  is  the  other  surface.  The  pneumatic 
foramen  is  on  the  anterior  side,  just  beyond  the  end  of  the  articular  sur- 
face. The  dorsal  border  of  the  bone  is  gently  and  evenly  convex  from 
a  little  beyond  the  proximal  extremity,  and  the  width  on  the  distal  three- 
fifths  is  nearly  uniform.  The  distal  extremity  of  the  bone  is  curved 
downward;  the  articular  surface  in  life  was  doubtless  a  vertical  oval. 

measurements. 

mm. 
Length 283 

Greatest  width  at  proximal  end 27 

Chord  of  proximal  articulation 17 

Width  of  shaft,  proximal  third 14 

Width  of  shaft,  distal  third--- 14 

Width  distal  extremity 18 

Thickness  of  shaft  at  middle  as  compressed 1.7 

The  second  wing  phalange  (PI.  XLIV,  Fig.  5)  lies  in  position  in  the 
right  wing,  but  is  somewhat  displaced  in  the  left.  It  is  much  smaller 
and  more  slender  than  the  first  phalange.  Its  proximal  border  is  nearly 
straight  and  transverse  to  the  axis  of  the  shaft;  it  ib  much  broader  than  the 
shaft.  The  under  border  of  the  bone  is  gently  concave  throughout, 
except  on  the  proximal  part,  where  the  concavity  is  deeper.  The  upper 
border,  gently  concave  at  the  proximal  end,  is  nearly  straight  thence  to 
near  the  extremity.  The  distal  extremity  is  quite  like  that  of  the  first 
phalange,  though  smaller. 


On  the  Osteology  of  Nvctosaurus.  147 

measurements. 

mm. 
Length — 211 

Width  proximal  extremity - - 17,  18 

Width  at  proximal  third _- 9,  10 

Width  at  distal  third 8,  9 

Width  of  distal  end — 9,  10 

The    third  phalange  has    the    proximal    extremity    preserved,    com- 
pressed from  above.     The  surface  seems  to  have  been   only  slightly  con- 
'  cave.     This  phalange,  like  the  preceding  one,  seems  to   have  been  pro- 
portionally more  slender  than  in  Pteratiodon. 

PELVIC  GIRDLE  AND  EXTREMITY. 

Pelvis.  PI.  XLI,  Fig.  1.  The  pelvis  lies  with  the  bones  nearly  in 
position,  the  sacrum  with  its  ventral  surface  uppermost,  the  innominate 
bones  separated  at  their  sutures  and  in  juxtaposition  with  the  sacrum,  the 
visceral  surface  also  uppermost. 

There  was  in  the  sacrum  (PI.  XLI,  Fig.  1,  s)  in  life  evidently  a 
considerable  concavity  transversely,  and  possibly  a  slight  concavity  longi- 
tudinally. It  is  composed  of  six  firmly  united  vertebra?,  the  sutural  lines 
between  the  centra  clearly  distinguishable.  The  vertebrae  decrease  in 
length  from  the  first  to  the  fifth;  the  sixth  is  slightly  longer  than  its 
predecessor.  The  centra  are  flattened  in  the  preserved  specimen,  though 
possibly  in  life  they  may  have  been  slightly  convex  transversely.  The 
sacral  ribs  show  no  indications  of  sutural  connections  anywhere,  and  are 
broadly  united  distally.  Between  them  the  oval  foramina  decrease  rapidly 
in  size,  and  slightly  approach  the  middle  line,  the  last,  that  between  the 
fifth  and  sixth  vertebrae,  being  almost  punctiform,  while  the  first  is  of 
considerable  size. 

Trie  first  process  is  broad,  with  a  broad,  oblique  surface,  terminating 
distally  in  a  free,  rounded  margin.  The  pelvic  brim  is  indicated  by  an 
angular  line  passing  outward  and  downward  obliquely  to  the  upper 
border  of  the  articular  surface  for  the  innominate  bone.  This  surface  is 
oval,  and  encroaches  obliquely  on  the  front  surface  of  the  sacrum;  beyond 
it  the  thin  margin  of  the  sacrum  does  not  present  a  sutural  surface  on  the 
ventral  side.  The  lateral  margins  approach  each  other  until  at  the  hind 
border  the  distance  between  them  is  less  than  half  that  at  the  brim  of 
the  pelvis. 

The  ilium  (PI.  XLI,  Fig.  1,  il)  has  a  long,  flattened  or  somewhat  pris- 
matic anterior  process,  reaching  as  far  forward  as  the  second  presacral 
vertebra.  The  process  is  apparently  curved  somewhat  backward  in  life, 
and  also  outward;  it  has  an  obtuse  anterior  extremity.     Posteriorly  the 


148  Field  Columbian  Museum — Geology,  Vol.  II. 

ilium  extends  a  short  distance  beyond  the  end  of  the  sacrum  as  a  short, 
obtuse  process.  It  sends  an  angular  expansion  upward  and  inward 
opposite  the  end  of  the  sixth  sacral  vertebra,  which  extends  five  or  six 
millimeters  above  the  margin  of  the  sacrum,  possibly  forming  a  sort  of 
roof  over  the  last  sacral  and  the  first  caudal,  and  approaching,  or 
possibly  meeting,  its  mate  in  the  middle.  The  flattened  or  ventral  por- 
tion (PI.  XLI,  Fig.  i,  ip)  of  the  ischio-pubis  is  somewhat  trapezoidal  in 
shape  with  the  symphysial  line  slightly  oblique  to  the  sacral  border. 
Both  bones,  separated  at  the  median  suture,  lie  with  the  visceral  surface 
uppermost,  and  both  present  a  considerable  concavity.  The  anterior 
border  begins  at  the  upper  margin  of  the  process,  which  articulates  with 
the  sutural  surface  described  on  the  lateral  margins  of  the  sacrum  oppo- 
site the  first  intercostal  foramen.  The  margin  is  thin  and  concave  as  far 
as  the  angular  process  for  the  attachment  of  the  prepubis.  This  process 
is  everted  from  the  brim  of  the  pelvis,  and  is  tipped  with  a  small,  oval, 
cartilaginous  or  articular  surface.  From  this  surface  the  margin,  some- 
what thicker,  recedes  in  a  straight  line  to  the  beginning  of  the  median 
symphysis.  The  symphysial  margin  is  thin  and  nearly  straight.  For 
the  first  fourth  of  its  length  it  seems  to  meet  its  mate,  if  at  all,  in  an 
harmonious  suture,  and  the  symphysis  in  front  may  have  been  somewhat 
rounded  or  subangular;  beyond  this,  however,  the  two  bones  meet  in  a 
very  oblique  surface,  attaining  a  width  of  four  or  five  millimeters  poste- 
riorly, and  the  two  bones  must  have  formed  a  thin  and  sharp  keel  when 
conjoined.  The  posterior  border  is  somewhat  thicker  than  the  anterior 
one.  It  begins  in  a  rather  acute  rounded  angle  at  the  base  of  the 
posterior  process  of  the  ilium,  and  is  directed  backward  and  ventrad  to 
the  angular  extremity  of  the  symphysis.  The  large  rounded  ischiadic 
(obturator)  foramen  is  situated  in  front  of  the  middle  of  the  bone, 
almost  directly  ventrad  to  the  acetabulum;  its  borders  are  smooth  and 
thin.  Between  this  foramen  and  the  margin  of  the  ilium,  there  is  a  con- 
siderable convexity,  representing  the  floor  of  the  acetabulum.  Its  dorsal 
margin  must  be  nearly  over  the  line  of  the  sacrum.  The  junction  of  the 
innominate  with  the  sacrum  is  by  a  narrow  concave  sutural  surface,  fitting 
on  the  margin  of  the  sacrum;  in  front  there  is  a  considerable  oval  surface 
on  the  anterior  part  of  the  bone,  which  fits  into  the  depressed  surface 
already  described,  on  the  sides  of  the  sacrum.  Posteriorly,  also,  the  pro- 
jection of  the  ilium  has  a  little  broader  attachment.  Dorsad  to  this 
junction  the  ilium  seems  to  have  projected  beyond  the  margin  of  the 
sacrum  slightly  in  the  middle,  expanding  in  the  angular  process  already 
described. 

Prepubes.    PI.  XLI,  Fig.  i,pp>     The  prepubes  are  very  nearly  as  they 
are  in  Pteranodon,  consisting  of  a  flat,  transverse  ribbon-like  band  meet- 


On  the  Osteology  of  Nyctosaurus.  149 

ing  in  a  somewhat  angularly  expanded  median  symphysis,  which  is  thor- 
oughly co-ossified,  and  with  an  anteriorly  directed,  somewhat  divergent, 
flat,  and  obtusely  pointed  anterior  process  at  each  side,  the  continuation 
of  the  posterior  flattened  portion  which  joins  the  pectineal  process  on 
the  everted  margin  of  the  pelvis.  This  process  is  somewhat  thickened 
at  its  posterior  extremity,  and  is  of  about  the  same  width  as  the  other 
parts  of  the  bone.  The  bone  in  the  specimen  had  been  torn  apart  at  the 
symphysis,  each  half  remaining  in  partial  juxtaposition  with  the  corre- 
sponding half  of  the  pelvis.  As  flattened  out  the  conjoined  bone  is 
much  too  wide  transversely  to  articulate  with  the  surfaces  on  the  margin 
of  the  pelvis;  too  wide  even  in  the  flattened-out  position  of  these  parts. 
It  seems  certain  that  the  extremities  must  have  articulated  with  the 
processes  described,  quite  as  I  have  already  described  the  conditions  in  the 
pelvis  of  Pteranodon,  and  it  therefore  follows  that  the  bone  in  life  must 
have  had  a  considerable  convexity,  in  a  broad,  U-shaped  form. 

There  are  no  indications  of  any  sutural  connection  in  the  bones  of 
the  pelvis,  except  such  as  I  have  described  with  the  sacrum  and  between 
the  two  halves.  Nevertheless,  the  presence  of  the  large  foramen,  the 
general  shape  of  the  bone  and  the  position  of  the  acetabulam  would  be  as 
one  would  expect  were  there  really  the  three  elements  present.  A  suture 
between  the  ischium  and  pubis  is  scarcely  to  be  expected,  in  consideration 
of  the  obliteration  of  the  sutures  elsewhere  in  the  skeleton.  I  am  there- 
fore inclined  to  look  with  favor  upon  the  view,  long  held  by  Seeley,  that 
the  pelvis  is  of  the  normal  reptilian  structure,  and  that  the  bones  in  front 
really  do  not  belong  to  it.  It  seems  very  probable  that  the  anterior  pro- 
longations of  the  prepubes  come  in  contact  with  the  posterior  ends  of 
the  parasternum,  and  that  the  whole  bone  is  merely  a  continuation  of  the 
abdominal  armature.  However,  I  must  admit  that  the  persistence  of  the 
sacral  and  symphysial  sutures,  permitting  the  pelvis  to  drop  apart  without 
distortion,  and  the  utter  obliteration  of  any  ischio-pubic  suture  is 
inexplicable. 

"  Naturalists  have  been  uncertain  as  to  the  number  of  bones  in  the 
pelvis  of  pterodactyls,  because  the  bones  blend  together  early  in  life,  as 
in  birds.  Some  follow  the  Amphibian  nomenclature,  and  unite  the 
ischium  and  pubis  into  one  bone,  which  is  then  termed  ischium,  when  the 
prepubis  is  termed  the  pubis,  and  regarded  as  removed  from  the 
acetabulum.  There  is  no  ground  for  this  interpretation,  for  the  sutures 
are  clear  between  the  three  pelvic  bones  in  the  acetabulum  in  some 
specimens,  like  Cycnorphamphus  Fraasii,  from  Solenhofen  and  some 
examples  of  Ornithocheirus  from  the  Cambridge  Greensand."* 

By    modeling  in   cardboard  and  clay  the  bones  of   the  pelvis   and 

•Seeley,  Dragons  of  the  Air,  p.  04. 


150  Field  Columbian  Museum — Geology,  Vol.  II. 

uniting  them  in  a  complete  basin,  with  the  necessary  curvatures,  it 
transpires  that  the  opening  of  the  pelvis  had  a  diameter  of  about  seven- 
eighths  of  an  inch,  while  the  outlet  could  have  measured  but  a  trifle  more 
than  half  an  inch. 

Femur.  PI.  XLIII,  Figs.  4,  5.  Both  femora  are  preserved,  separated 
by  a  short  distance  from  the  pelvis.  The  neck  is  directed  upward  and  at 
a  slight  angle  inward;  it  is  cylindrical,  the  head  only  a  little  dilated  and 
with  its  convexity  only  a  little  oblique  to  the  axis  of  the  bone;  that  is,  the 
plane  of  the  rim  is  nearly,  but  not  quite,  rectangular  to  the  axis  of  the 
shaft.  The  trochanter  stands  a  little  to  the  outer  side  of  the  middle  axis 
of  the  bone.  From  its  upper  angle  a  ridged  process  runs  backward  for  a 
short  distance,  to  the  inner  side  of  which,  a  little  below  the  free,  upper 
concave  margin  of  bone,  there  is  a  small  pneumatic  opening.  On  the 
outer  side,  the  margin  of  the  shaft  is  convex  for  a  short  distance,  and  is 
then  concave  throughout  to  the  extremity.  On  the  inner  side  above,  the 
margin  is  correspondingly  concave;  below  this  to  the  condyle  it  is  con- 
vex. The  upper  part  of  the  bone  was  evidently,  in  life,  nearly  cylindrical; 
below  it  seems  to  have  been  wider  and  somewhat  flattened.  Near  the 
middle  behind,  beginning  a  little  above  the  condylar  surface,  there  is  a 
narrow,  elongated,  longitudinal  ridge  for  the  attachment  of  a  muscle. 
The  distal  articular  surface  cannot  be  clearly  made  out  in  the  crushed 
specimens.  The  bone  had  in  life,  apparently,  a  marked  anterior  curva- 
ture, as  in  Pteranodon. 

MEASUREMENTS   OF   FEMUR. 

mm. 

Length 81 

Diameter  of  neck 6 

Diameter  of  shaft,  upper  third 7 

Diameter  through  condyles  as  crushed , 13 

Femur  of  Pteranodon  ingens  Marsh,  PI.  XLIII,  Figs.  1-3.  The  con- 
vexity of  the  head  is  regular,  covering  nearly  half  of  a  circle  transversely, 
probably  a  little  less  in  the  conjugate  diameter,  the  surface  thus  forming 
an  oval  or  ovate  figure,  the  plane  of  whose  base  is  nearly  at  right  angles 
to  the  long  diameter  of  the  bone.  The  convex  surface  is  sharply  limited 
from  the  neck.  The  neck  is  cylindrical,  rather  stout,  and  is  directed 
nearly  vertically  downward.  The  rounded  and  moderately  prominent 
trochanter  is  placed  over  the  middle  of  the  shaft,  descending  into  the 
concavity  at  the  side  of  the  neck,  and  externally  separated  from  the 
margin  of  the  bone.  The  shaft  is  nearly  of  equal  width  throughout; 
doubtless  in  life  it  was  nearly  cylindrical,  with  a  strong  anterior  curvature, 
and  a  flattening  in  the  popliteal  region.  The  sharp  margin  of  the  inner 
condvle  encompasses  nearly  half  a  circle.     The  outer  condyle,  though 


On  the  Osteology  of  Nyctosaurus.  151 

extending  further,  is  much  less  in  extent.  The  inner  distal  articular  sur- 
face is  the  larger,  and  is  separated  from  the  inner  surface  by  a  distinct 
ridge,  especially  posteriorly. 

Tibia.  PI.  XLIV,  Fig.  3.  The  tibia  is  a  slender,  straight  bone,  mod- 
erately expanded  at  the  upper  extremity.  The  margin  of  the  articular 
surface  above  is  nearly  transverse  to  the  longitudinal  axis.  The  width 
contracts  chiefly  at  the  expense  of  the  posterior  margin  to  the  lower  part 
of  the  upper  fourth  of  the  bone,  the  shaft  below  being  of  nearly  uniform 
width.  The  trochlear  surface  at  the  distal  extremity  is  pulley-shaped, 
covering  about  half  of  a  circle,  perhaps  more,  and  has  a  moderately 
deep  groove.  The  sutural  union  between  the  tibia  proper  and  the  prox- 
imal tarsal  bone,  or  bones,  is  entirely  obliterated.  The  bones  of  the  two 
sides  are  compressed  in  different  positions,  the  left  one  from  the  side,  the 
right  one  from  nearly  in  front ;  the  width  above  is  considerably  greater 
in  the  former  than  in  the  latter,  indicating  but  comparatively  little  ex- 
pansion of  the  upper  part  from  side  to  side. 

There  is  no  trace  of  any  fibula,  either  in  the  preserved  remains  or  in 
any  tibial  articulation. 

MEASUREMENTS   OF   TIBIA. 

mm. 

Length T 133(132) 

Width  above '. 15  (  11) 

Width  of  shaft  at  upper  end  of  middle  third-- 7  (    6) 

Width,  lower  third 6(    6) 

Antero-posterior  diameter  of  trochlea 6(    6) 

Foot.  But  a  single  metatarsal  and  one  phalange  are  present  in  this 
specimen.  These,  however,  agree  so  well  with  the  corresponding  bones 
of  Pteranodon  that  I  doubt  not  the  foot  was  quite  similar  to  that  of  the 
former  genus.  This  metatarsal  is  expanded  at  its  proximal  end  and 
gently  convex  on  the  trochlear  end.  It  measures  35  mm.  in  length,  2  mm. 
in  width  at  the  upper  fourth  and  4  mm.  at  either  extremity.  The  bone  is 
compressed  from  side  to  side.  The  phalange,  flattened  on  the  side,  has 
a  length  of  14  mm.  The  distal  end  has  the  extremity  convex,  its  chord 
rectangular  to  the  long  axis  of  the  bone  ;  its  width  is  3  mm.  The 
proximal  end  is  truncated  or  gently  concave  ;  its  width  is  about  4  mm. 
The  shaft  in  the  middle  is  scarcely  narrowed  from  the  proximal  end.  I 
repeat  here,  briefly,  the  description  of  the  foot  of  Pteranodon,  from  my 
paper  in  the  Kansas  University  Quarterly,  vol.  vi,  page  50,  with  some 
changes. 

The  first  four  metatarsals  are  very  slender,  straight,  and  contiguous 
with  each  other,  each  having  a  flattened  proximal  articular  surface  and 
a  rounded  trochlear  distal  extremity.     The  metatarsal  of  the  fifth  toe  is 


152  Field  Columbian  Museum — Geology,  Vol.  II. 

rudimentary,  subtriangular  in  shape,  with  the  obtusely  pointed  distal  part 
curved,  altogether  resembling  an  obtuse  claw.  The  first  toe  has  a  single 
phalange,  which  is  long,  cylindrical,  gently  curved,  and  obtusely  pointed. 
The  second  toe  has  two  phalanges,  the  first  of  which  is  elongate  and 
grooved  with  a  distal  trochlear  articulation.  The  second  phalange 
resembles  the  first  of  the  first  toe,  but  is  shorter.  The  third  toe  has  four 
phalanges,  the  proximal  one  of  which  is  like  that  of  the  second  toe,  but 
is  elongate;  the  second  is  broader  than  long;  the  third  is  like  the  first,  but 
is  shorter;  the  fourth  is  a  short,  scarcely  curved  and  obtusely  pointed  claw. 
The  fourth  toe  has  five  phalanges,  of  which  the  first,  fourth,  and  fifth 
resemble  the  first,  third,  and  fourth  of  the  third  toe,  the  second  and  third 
the  second  of  the  same  toe.  This  toe  is  the  longest.  The  fifth  has  no 
phalanges.  I  may  add  that  the  foot  from  which  these  measurements  were 
taken  was  found  together,  with  the  bones  in  place  or  but  little  displaced, 
and  has  been  so  mounted  in  the  University  of  Kansas  Museum.  I  have 
repeatedly  examined  these  bones,  and  am  confident  that  the  number  of 
phalanges  are  as  I  have  given  them ;  that  is,  there  is  an  absence  of  the 
claws  on  the  first  and  second  toes.  The  measurements  of  this  specimen 
are  as  follows  : 

mm. 

Femur,  length 260 

Diameter  of  head 20 

Width  of  condyles - 30 

Tibia,  length 362 

Metatarsals,  length ^ -- 101,  105,95,  80,  25 

Phalange,  first  digit,  length 41 

Phalanges,  second  digit,  length 25,  31 

Phalanges,  third  digit,  length 35,  4,  27,  12 

Phalanges,  fourth  digit,  length 40,  3,  3,  26,  12 

Ossified  tendons.  Numerous  thin,  flat,  striated  bones  are  lying  on 
the  matrix  associated  with  the  anterior  extremity,  which  can  only  be 
regarded  as  tendinous  ossifications.  One  of  these  on-  each  side  is  lying 
by  the  side  or  upon  the  pteroid  bone,  with  its  pointed  extremity  near 
its  proximal  end.  They  measure  one  hundred  to  one  hundred  and  twenty 
millimeters  in  length,  with  a  greatest  breadth  of  twelve  millimeters.  Two 
others  are  lying  by  the  side  of  the  proximal  end  of  the  right  wing 
metacarpal;  they  are  somewhat  shorter  and  have  the  flattened  fimbri- 
ated end  distad.  Another  is  lying  by  the  side  of  the  distal  end  of  the 
same  bone.  There  is  a  shorter,  more  fan-shaped  one  by  the  right  humerus, 
and  fragments  of  others  are  scattered  about  the  arms.  Altogether  there 
are  seven  of  these  of  about  one  hundred  millimeters  in  length.  Their 
texture  is  striate,  as  though  composed  of  slender,  ossified,  tendinous  fibers, 


On  the  Osteology  of  Nyctosaurus.  153 

altogether  reminding  one  very  much  of  similar  tendinous  ossifications 
in  the  legs  of  many  birds. 

A  number  of  other  slender,  rib-like,  more  or  less  fragmentary  bones 
are  observed  scattered  about  the  slab  near  the  body  of  the  specimen, 
of  which  I  am  not  at  all  certain,  though  I  suspect  that  some  of  them 
are  ventral  ribs,  perhaps  attached  during  life  to  the  extremity  of  the 
flat  parasternal  structures  already  described.  One  of  these  bones,  lying 
by  the  lateral  margin  of  the  sacrum  is  about  forty  millimeters  in  length 
and  is  gently  curved.  It  is  flattened  at  one  end,  measuring  nearly  three 
millimeters  in  width,  cylindrical  at  the  other,  and  not  more  than  one 
millimeter  wide.  Another,  lying  back  of  the  pelvis,  of  about  the  same 
length  is  also  slightly  curved,  one  millimeter  wide  at  one  end  and 
about  three-tenths  of  a  millimeter  in  width  at  the  other  end.  There 
are  also  parts  of  several  other  bones  which  seem  to  be  similar  to  these. 

SYSTEMATIC    POSITION. 

Three  specimens  ascribed  to  Nyctosaurus  are  now  known  —  the  type 
described  briefly  by  Marsh,  the  one  in  the  University  of  Kansas  Museum 
described  by  me  in  1892,  and  the  present  one.  Marsh  must  have  known 
more  than  one  specimen,  however,  in  which  additional  specimens  he 
later  recognized  the  essential  generic  characters.  The  three  specimens 
differ  materially  in  size,  that  described  by  Marsh  being  the  largest,  and 
the  Kansas  University  specimen  the  smallest.  In  the  smallest  speci- 
men the  coracoid  and  scapula  are  still  distinguished  by  a  separable 
suture.  Furthermore,  the  separated  arches  of  the  dorsal  vertebrae,  and 
the  distinction  of  the  elements  of  the  atlas  all  indicate  a  young  animal. 
On  the  other  hand,  the  present  specimen  has  all  of  its  sutures  obliter- 
ated, except  that  between  the  atlantal  intercentrum  and  the  axial  inter- 
centrum,  characters  which  may  be  ascribed  to  an  adult  condition.  Among 
the  characters  given  by  Marsh,  is  the  separated  coracoid  and  scapula, 
but  I  suspect  that  this  was  derived  from  a  smaller  specimen  than  the 
one  which  he  originally  named  Pteranodon  gracilis.  I  do  not  think 
that  the  absolute  differences  in  size  are  sufficient  to  separate  the  speci- 
mens specifically,  in  that  we  know  that  similar  differences  are  ascribed 
to  other  pterodactyls  by  some  authors.  In  order,  however,  to  make  the 
comparative  differences  between  these  specimens  clearer  I  have  reduced 
them  to  a  common  standard,  using  the  humerus  as  100  in  each.  In  addi- 
tion, I  give  like  comparative  measurements  of  certain  species  of  Pterodac- 
tylus,  derived  from  figures  given  by  Zittel: 


154  Field  Columbian  Museum — Geology,  Vol.  II. 


Su  SD  SU  g§  -gu  « 

2/-  Sj  5£  «*>  £iS  1 

gte  ^  gS  85  £* 

z  z  z  £  £  £ 

Humerus ioo  ioo  ioo  ioo  ^ioo  ioo 

Ulna... 165  165  ...  136  148  153 

Metacarpal 257  275  ...  210  106  105 

First  Phalange 324  327  ...  268  161  160 

Second  Phalange 241  ....  ...  172  142  129 

Femur 93  93  —  106  109  107 

Tibia 151  151  ...  150  153  144 

Metacarpal ' 100  100  100  —  —  — 

Ulna 64  60  62 

First  Phalange 126  iiq  115  —  —  — 

It  is  observed  that  there  is  a  striking  agreement  in  these  specimens, 
except  in  the  metacarpals,  the  differences  elsewhere  being  scarcely  more 
than  one  might  expect  in  the  measurement  of  bones  differently  affected 
by  the  compression  to  which  they  have  been  subjected.  Now,  we  may 
consider  this  variation  of  specific  value  and  give  to  each  of  these  three 
specimens  a  different  name;  or  we  may,  as  is  far  more  reasonable, 
consider  the  metacarpal  as  a  variable  bone  in  the  individual,  as  it  is 
in  the  species  and  groups,  and  refer  them  all  to  one  species.  This 
I  have  no  hesitation  in  doing.  There  is,  then,  but  a  single  species 
of  Nyctosaurus  now  known  among  the  specimens  referred  to  the  genus; 
it  should  be  called  Nyctosaurus  gracilis  Marsh. 

In  specimens  of  Pteranodon  ingens  there  is  not  a  little  variation  in 
size,  especially  in  the  length  of  the  wing  metacarpal,  which  I  have 
observed  to  vary  from  580  to  615  millimeters,  the  longest  that  I  have 
ever  known  from  the  Kansas  chalk.  It  is  very  certain,  I  think,  that 
absolute  identity  of  size  cannot  be  relied  upon  to  distinguish  the  differ- 
ent species  of  pterodactyls,  nor  do  I  think  that  the  relative  or  propor- 
tional lengths  of  the  finger  bones  should  receive  too  much  weight; 
the  different  species  evidently  varied  individually  within  certain  limits. 

In  my  first  paper  on  Nyctosaurus,  I  discussed  briefly  the  so-called 
species  of  Pteranodon,  P.  nanus,  and  P.  comptus,  suspecting  that  one  or 
both  of  them  belonged  with  Nyctosaurus. 

A  wider  acquaintance  with  Kansas  pterodactyls,  both  in  the  laboratory 
and  in  the  field  strengthens  my  belief  that  both  of  these  names  are 
synonyms  of  N.  gracilis. 

No  small  species  from  the  Kansas  chalk  can  be  referred  definitely  to 
Pteranodon,  so  far  as  my  own  knowledge  goes,  and  I  have  seen  hundreds 
of  specimens.  P.  nanus  presents  the  strong  lateral  crest  of  the  humerus 
which  I  am  satisfied  is  a  diagnostic  characteristic  of    Pteranodon.     Al- 


On  the  Osteology  of  Nyctosaurus.  155 

though  the  author  expressly  stated  that  the  "coracoid  and  scapula  were 
firmly  anchylosed"  a  character  seen  in  the  present  specimen  of  Nycto- 
saurus, I  feel  pretty  confident  that  the  type  of  P.  nanus  does  not  have  the 
articular  extremity  of  the  scapula  so  characteristic  of  Nyctosaurus.  The 
description  of  P.  comptus  might  apply,  except  in  size,  to  either  Nycto- 
saurus or  Pteranodon.  I  refer  the  species  to  the  former  genus  because  of 
its  small  size,  but  its  synonymy  is  not  assured.  That  a  better  basis  for  an 
opinion  may  be  given  the  reader,  I  here  reproduce  all  that  Marsh  has 
written  upon  Nyctosaurus  and  the  two  small  species  which  he  referred  to 
Pteranodon. 

"  One  of  the  smallest  American  species  yet  found  is  represented  in  the 
Yale  Museum  by  several  bones  of  the  wing,  a  number  of  vertebrae  and 
the  nearly  complete  pelvis.  The  wing  bones  preserved  are  elongated 
and  very  slender.  The  pelvis  is  unusually  small,  and  there  are  five 
vertebrae  in  the  sacrum.     The  last  of  the  series  indicates  that  the  tail  was 

short.     The  following  are  the  principal  dimensions  of  this  specimen: 

mm. 

Length  of  ulna 187 

Length  of  metacarpal  of  wing  finger — 300 

Antero-posterior  diameter  of  outer  condyle  at  distal  end 15 

Tranverse  diameter  of  shaft,  above  condyles . 13 

Length  of  first  phalanx  of  wing  finger . 347 

Extent  of  five  vertebrae  of  sacrum 57 

"This  species,  which  may  be  called  Pteranodon  gracilis,  was  about  two- 
thirds  the  size  of  P.  velox  Marsh.  It  probably  measured  about  ten  feet 
between  the  tips  of  the  expanded  wings."* 

"  Pteranodon  comptus,  sp.  nov.  The  smallest  Pterodactyle  known  from 
American  strata  is  indicated  by  portions  of  three  skeletons  in  the  Yale 
Museum.  Among  these  remains  are  two  distal  ends  of  the  characteristic 
metacarpal  of  the  wing  finger,  other  portions  of  the  wing  bones,  and  two 
sacral  vertebrae.  The  large  metacarpal  is  very  slender  and  elongated, 
and  its  outer  distal  condyle  has  its  superior  margin  elevated  above  the 
shaft,  and  terminated  proximally  in  a  point.  The  ulna  is  comparatively 
large,  and  the  proximal  carpal  has  an  oval  air  cavity  on  its  radial  side. 
The  sacral  vertebrae  have  their  centra  short,  and  medially  constricted. 

"  The  principal  measurements  of  the  remains  of  thisspecies  are  as  follows: 

mm. 

Greatest  diameter  of  ulna  at  distal  end 15 

Transverse  diameter  of  proximal  carpal 17 

Antero-posterior  diameter  of  outer  distal  condyle  of  wing  metacarpal 12  8 

Longitudinal  extent  of  condyle 11.6 

Transverse  diameter  of  shaft  above  condyle -- 11.5 

Length  of  medial  sacral  vertebra 9 

Transverse  diameter  of  centrum 8.4 

♦Marsh,  Amer.  Journ.  Sci.  June,  1876,  p.  508. 


156  Field  Columbian  Museum — Geology,  Vol.  II. 

"  The  above  specimens  are  all  from  the  Upper  Cretaceous  of  Western 
Kansas."* 

"  Nyctosaurus,  gen.,  nov."  A  second  genus  of  American  Pterodactyls 
is  represented  in  the  Yale  Museum  by  several  well-preserved  specimens. 
This  genus  is  nearly  related  to  Pteranodon,  but  may  be  readily  distin- 
guished from  it  by  the  scapular  arch,  in  which  the  coracoid  is  not  co  ossi- 
fied with  the  scapula.  The  latter  bone,  moreover,  has  no  articulation  at 
the  distal  end,  which  is  comparatively  thin  and  expanded.  The  type  of 
this  genus  is  Pteranodon  gracilis  Marsh,  which  may  now  be  called  Nycto- 
saurus gracilis.  It  was  a  Pterodactyl  of  medium  size,  measuring  about 
eight  to  ten  feet  between  the  tips  of  the  expanded  wings.  Its  locality  is 
in  the  Upper  Cretaceous  of  Western  Kansas.  The  type  specimens  of  all 
the  above  species  are  preserved  in  the  Museum  of  Yale  College."  f 

"  In  the  same  geological  horizon  with  the  gigantic  forms  (Pterano- 
don beds)  the  remains  of  a  single  small  Pterodactyl  have  been  found. 
Th;s  animal  was  more  diminutive  than  the  Jurassic  species  \Dermodactylus 
montanus],  having  a  spread  of  wings  not  more  than  three  or  four 
feet.  The  jaws  were  proportionally  more  slender  than  in  the  larger  Cre- 
taceous species,  and  no  teeth  have  been  found  with  them.  The  humerus 
had  a  small  head  and  an  enormous  radial  crest,  which  curved  downwards. 
The  scapula  and  coracoid  were  firmly  ankylosed.  Some  of  the  trunk 
vertebrae  have  very  long  transverse  processes,  or  ankylosed  ribs,  curved 
backward.     Some  dimensions  of  this  specimen  are  as  follows  : 

Length  of  humerus 62 

Greatest  diameter  of  head 12 

Transverse  diameter  across  radial  crest 30 

Greatest  diameter  of  distal  end 16 

Vertical  diameter  of  humeral  glenoid  cavity 13 

Transverse  diameter 6 

"  This  species  may  be  called  Pteranodon  nanus.  Its  known  remains 
were  found  by  Mr.  S.  W.  Williston,  in  the  Middle  Cretaceous  of  Western 
Kansas."  % 

"The  name  Nyctosaurus,  applied  by  the  writer  to  this  group,  appears 
to  have  been  preoccupied,  and  hence  may  be  replaced  by  Nyctodactylus. 
The  only  species  known  is  Nyctodactylus  gracilis.''''  jj 

It  is  seen  that  but  five  vertebrae  are  referred  to  the  sacrum  of  the 
type  of  Nyctosaurus  gracilis  ;  if  this  be  a  real  character  one  would  not 
question  the  distinctness  of  the  species.  Inasmuch  as  Pteranodon  has 
six  vertebrae  in  the  sacrum  and  one  or  more  lumbars  or  false  sacrals,  as  in 

♦Marsh,  1.  c,  p.  509. 

t  Marsh,  Amer.  Journ.  Sci.  Dec,  1876,  p.  480. 

%  Marsh,  Amer.  Journ.  Sci.  April,  1881,  p.  343. 

II  Marsh,  Amer.  Journ.  Sci.  April,  1881,  p.  343,  footnote. 


On  the  Osteology  of  Nyctosaurus.  157 

the  present  specimen  of  Nyctosaurus,  I  believe  that  this  number  will  be 
found  common  to  all  the  Kansas  pterodactyls.  I  think  that  Marsh  must 
have  been  in  error  in  ascribing  but  five  to  the  sacrum.  Should  he,  how- 
ever, be  correct  I  would  suggest  the  name  N.  leptodactylus  for  the  present 
species! 

In  view  of  the  foregoing  I  offer  the  following  as  the  synonymy  of 
this  genus  and  species  : 

NYCTOSAURUS. 

Marsh,  Amer.  Journ.  Sci.,  xii,  p.  480,  Dec,  1876.  Nyctodactylus 
Marsh,  Amer.  Journ.  Sci.,  xxii,  p.  343,  April,  1881  ;  ibid.,  xxvii,  p.  423, 
May,  1884.  Williston,  Kans.  Univ.  Quart.,  i,  p.  2,  5,  1893;  Journ.  Anat- 
omy, i,  p.  297,  1902  ;  Journ.  Geology,  x,  p.  520,  July-Aug.  1902. 

NYCTOSAURUS    GRACILIS. 

Pteranodon  gracilis  Marsh,  Amer.  Journ.  Sci.,  xi,  p.  508,  June,  1876. 

Nyctosaurus  gracilis  Marsh,  Amer.  Journ.  Sci.  xii,  p.  480,  Dec.  1876. 

Nyctodactylus  gracilis  Marsh,  Amer.  Journ.  Sci.  xxi,  p.  343,  April, 
1881;  Williston,  Kans.  Univ.  Quart.,  i,  p.  ii,  1893;  Zittel's  Paleontology 
(Eastman),  vol.  ii,  p.  255,  Fig.  361,  1902. 

(?)  Pteranodon  comptus  Marsh,  Amer.  Journ.  Sci.  xi,  508,  June,  1876; 
Williston,  Kans.  Univ.  Quart,  i,  p.  11,  June,  1893. 

(?)  Pteranodoti  nanus  Marsh,  Amer.  Journ.  Sci.,  April,  1881,  p.  343; 
Williston,  Kans.  Univ.  Quart,  i,  p.  11,  June,  1893. 

Of  the  remaining  species  of  Kansas  pterodactyls,  six  have  been 
described,  two  of  which,  P.  umbrosus  and  P.  harpyia  Cope,  are  admittedly 
identical  with  previously  described  forms,  leaving  ingens,  occidentalis,  velox, 
and  longiceps  Marsh.  No  real  attempt  was  made  to  separate  P.  longi- 
ceps  from  those  previously  named,  nor  could  there  have  been,  since  only 
the  skull  was  known  in  this  species  to  the  describer,  while  the  skull  was 
not  known  in  either  of  the  other  species.  It  may  be  identical  with 
either  occidentalis  or  velox.  possibly  with  both.  The  characters  given  by 
Marsh  to  distinguish  the  species  have  little  value,  though  I  believe  there 
are  three  distinct  ones  of  the  genus,  known  from  the  Kansas  chalk. 
Two  of  these  species  are  at  once  distinguishable  by  the  structure  of  the 
humerus,  especially  of  its  radial  or  lateral  crest.  In  P.  ingens  this  crest 
is  rounded  and  obtuse;  in  one  or  the  other  of  the  smaller  forms  it  is  more 
elongate  and  of  a  different  shape.  Furthermore,  among  the  smaller 
specimens  there  appear  to  be  two  different  types  of  terminal  wing  pha- 
lange, one  nearly  straight  and  the  other  curved  falciform,  as  in  P.  ingens. 
If  the  smaller  form  with  the  curved  phalange  should  prove  not  to  be  the 


158  Field  Columbian  Museum — Geology,  Vol.  II. 

young  of  P.  ingens,  as  is  not  likely,  then  we  have  at  least  three  distinctly 
different  species  of  the  genus,  perhaps  a  fourth  in  P.  comptus. 


A  much  more  interesting  question  is  :  What  relation  do  the  genera, 
Nyctosaurus,  Ornithocheirus,  and  Pteranodon  (Omithostoma)  bear  to  each 
other  and  to  Pterodactylus  ? 

The  classification  which  has  hitherto  seemed  the  best  to  display  the 
relationship  of  these  forms  is  the  following  : 

Suborder  Pterodactyloidea.  Tail  short;  wing  metacarpal,  at  least  as 
long  as  the  bones  of  the  antebrachium;  fifth  digit  of  pes  vestigial,  with- 
out phalanges. 

Family  Pterodactylidae.  Scapula  not  articulating  with  supraneural 
facet. 

Genus  Pterodactylus.     Teeth  present. 

Genus  JVyctosaurus.     No  teeth. 

Family  Ornithocheiridae.  Scapula  with  an  articular  facet  united  with 
neural  facet  of  the  notarium. 

Genus  Omitkocheirus.     Jaws  with  teeth. 

Genus  Pteranodon  {Ornithostoma).     Jaws  without  teeth. 

However,  a  better  knowledge  of  the  genus  JVyctosaurus  convinces 
me  that  its  relationship  is  closer  with  Ornithocheirus  than  with  Pterodacty- 
lus; that  it  has  gone  much  further  in  specialization  in  the  same  direction 
with  Ornithocheirus  and  Pteranodon.  Very  little  now  remains  to  be 
known  of  the  osteology  of  both  these  genera,  and  not  much  of  Ortii. 
thocheirus .  Their  characters  as  a  group  may  be  summed  up  as  follows. 
While  some  parts  of  the  skeleton  of  Ornithocheirus  are  yet  unknown,  I 
am  confident  that  future  discovery  will  produce  nothing  very  discrepant. 

Ornithocheiridoz.  Head  elongate,  slender;  no  antorbital  vacuity; 
internal  nares  large;  eight  cervical,  ten  dorsal  {Pteranodon?},  six 
sacral,  and  ten  to  twelve  caudal  vertebrae  present,  the  last  dorsal  co-os- 
sified with  the  sacrum;  first  three  or  four  dorsal  vertebrae  united  into  a 
notarium,  with  stout,  anchylosed  ribs  articulating  with  the  sternum;  pos- 
terior dorsal  ribs  very  slender,  single-headed,  and  nearly  straight;  three 
or  four  pairs  of  flattened  V-shaped  ventral  ribs  present.  Ilium  much 
elongated;  ischio-pubis  with  an  obturator  foramen;  prepubes  band-like, 
co-ossified,  with  an  anterior,  flattened  projection  on  eaCh  side.  Coraco- 
scapula  with  only  a  slight  projection  below  the  glenoid  cavity,  co-ossified 
in  the  adult;  scapula  but  little  longer  than  the  coracoid,  not  narrowed 
distally.  Three  carpals  present;  forearm  much  longer  than  humerus;  third 
and  fourth  metacarpals  very  short,  pointed  proximally,  not  articulating 
with  carpus;  second  metacarpal  thread-like  proximally;  fifth  metacarpal 


On  the  Osteology  of  Nyctosaurus.  159 

much  longer  than  forearm;  phalanges  proportionally  long.  No  fibula 
present;  two  tarsals  only;  fifth  digit  without  phalanges. 

Ornithocheirina.  Upper  end  of  scapula  thickened,  articulating 
with  a  supraneural  plate.     Head  with  a  prominent  parieto-occipital  crest. 

Ornithocheirus.     Jaws  with  teeth. 

Pteranodon  (Omithostomd).     Jaws  wholly  edentulous. 

NyctosaurincB.  Scapula  flattened  spatulate  above,  not  articulating 
with  supraneural  plate.  Humeral  crest  constricted;  humerus  propor- 
tionally short,  the  digit  long;  no  sagittal  crest. 

Nyctosaurus,  Ornithodesmus  (?). 

In  contradistinction  to  these  characters  I  would  define  the  Ptero- 
dactylida  as  follows:  I  have  never  seen  any  specimen  of  this  genus,  and 
must,  therefore,  rely  entirely  upon  the  descriptions  and  figures.  The 
characters  hence  are  in  a  measure  provisional. 

Pterodactylida.  A  distinct  antorbital  foramen  present,  sometimes 
partly  confluent  with  the  nares;  occiput  not  produced,  jaws  always  with 
teeth.  No  consolidation  of  the  thoracic  vertebrae  or  anchylosis  of  the 
sternal  ribs,  the  posterior  ribs  less  slender.  More  than  ten  vertebras  in 
the  dorsal  region  and  less  than  six  in  the  sacrum.  Prepubes  never  co-ossi- 
fied in  the  middle,  and  without  anterior  prolongation.  Scapula  longer 
than  the  coracoid,  more  or  less  narrowed  distally.  Humerus  and  legs 
relatively  large,  the  forearm  and  wing  finger  relatively  small;  all  the  meta- 
carpals articulating  with  the  carpus.     A  fibula  present. 

I  am  sure  that  all  these  characters  are  generalized  ones,  even  as  the 
genus  is  older  than  those  placed  in  the  first  group.  It  seems  to  me 
especially  that  the  shortening  of  the  back,  the  consolidation  of  the  early 
dorsal  vertebrae,  and  the  elongation  of  the  sacrum,  with  the  greater  elonga- 
tion of  the  wing  digit,  are  better  evidences  of  relationships  than  is  the 
presence  of  the  peculiar  scapular  articulation. 


Certain  conclusions  as  to  the  habits  of  the  Ornithocheiridd,  as  I  here 
define  the  family,  seem  inevitable  from  a  better  knowledge  of  their  struc- 
ture. Some  of  these  conclusions  I  have  already  presented  in  a  former 
paper,  and  a  further  study  only  strengthens  my  belief  in  their  justness. 

The  neck  was  strong,  with  limited  torsion,  but  with  great  power  and 
effectiveness  in  the  antero-posterior  flexion,  thus  rendering  the  beak  very 
effective  in  striking.*  The  marked  posterior  projection  of  the  hind 
zygaphophyses  of  the  last  cervical  vertebra,  quite  unlike  those  of  any 
other  vertebrae  in  the  column,  indicates,  not  that  the  neck  turned  back- 

*  Plieninger  (op.  cit.)  misquotes  me  in  saying  that  "  Williston  glaubt,  dass  diese  Art  der 
Articulation  die  Bewegung  des  Halses  in  verticaler  Kichtung  von  vorne  nach  binten  eingeschrankt 
hat."  What  I  said  was:  "  Such  a  mode  of  articulation  would  seem  to  limit  the  motion  to  one  in  a 
vertical,  antero-posterior  plane,  while  greatly  strengthening  the  joints."— Kans.  Univ.  Quart.,  vi,  p.  39. 


160  Field  Columbian  Museum — Geology,  Vol.  II. 

ward  at  this  place,  but  that  it  curved  forward  more  after  the  way  of  birds, 
a  position  compatible  with  the  upright  attitude.  The  whole  structure 
of  the  neck,  the  elongated  vertebras,  the  transverse  centra,  and  lateral 
exapophysial  articulations,  the  absence  of  transverse  processes,  all  remind 
one  of  the  neck  in  the  cryptodire  testudinates,  where  the  neck  is  capable 
of  much  and  effective  antero-posterior  flexion. 

The  articulation  of  the  head  of  the  femur,  with  the  basal  plane  of  its 
convexity  nearly  at  right  angles  to  the  long  axis  of  the  bone,  and  the 
posterior  position  of  the  acetabulum,  carry  conviction  to  me  that  the 
femora  could  not  have  been  brought  parallel  in  the  same  direction  with- 
out dislocation  from  the  sockets,  whatever  attitude  the  animal  may 
have  assumed.  The  articulation  of  the  distal  end  of  the  tibia  further- 
more shows  that  the  metatarsus  could  not  have  been  extended  to  a  right 
angle;  that  is,  Pteranodon  could  not  have  been  plantigrade.  The  greater 
extension  must  have  been  between  the  metatarsus  and  phalanges;  in  other 
words,  the  creature  must  have  been  digitigrade  in  ambulation.  The  flat- 
tened proximal  ends  of  the  metatarsals  indicate  a  compact  and  closely 
united  foot,  and  the  bones  have  been  so  found  in  specimens  of  Pteranodon. 
The  toes  in  Pteranodon,  and  doubtless  in  this  genus  also,  were  practically 
clawless,  and  the  outer  toes  were  much  the  longer.  The  animal  was 
incapable  of  seizing  or  holding  with  the  feet. 

Nor  could  a  very  great  flexion  at  the  knee  have  been  possible,  as  I 
think  the  figures  of  the  femur  of  Pteranodon  ingots  will  indicate.  If 
the  animal  was  quadrupedal,  it  must  have  been  in  a  crawling  attitude, 
with  both  legs  and  arms  widely  extended. 

APATOMERUS  MIRUS,  GEN.  ET.  SP.  NOV. 

In  the  University  of  Kansas  Quarterly,  vol.  iii,  p.  3,  I  described  and 
figured  a  remarkable  bone  from  the  Lower  Cretaceous  of  Clark  County, 
Kansas,  which  I  hesitatingly  referred  to  some  crocodile -like  animal, 
because  I  was  at  a  total  loss  where  else  to  place  it,  my  knowledge  of  the 
pterodactyl  anatomy  then  being  less  than  at  present.  The  figure  and 
description  are  reproduced  in  vol.  iv  of  the  University  Geological  Sur- 
vey of  Kansas,  p.  90,  as  follows:  "The  upper  end  of  a  femur  found  in 
the  same  region  appears  to  belong  to  the  same  kind  of  an  animal,  as 
does  the  vertebra  described  above.  The  shape  is  not  unlike  that  of  a 
human  femur,  with  the  trochanters  evidently  small  and  placed  much 
below  the  level  of  the  head.  The  neck  is  stout,  the  head  gently  convex, 
with  an  angular  border.  The  shaft  below  the  trochanters  is  somewhat 
flattened  from  before  backward,  but  becomes  more  cylindrical  below.  The 
shaft  is  hollow,  with  firm  walls  not  more  than  one-third  of  an  inch  in 
thickness.     The  portion  preserved  measures  210  mm." 


On  the  Osteology  of  Nyctosaurus.  161 

I  am  now  satisfied  that  the  femur  in  question  belongs  to  a  heavy-boned 
pterodactyl  or  some  allied,  hitherto  unknown,  animal.  The  very  peculiar 
head  of  the  bone  with  its  articular  convexity  directed  upward,  the  posi- 
tion of  the  trochanter,  the  hollow  shaft  and  its  curvature  are  characters 
all  found  in  pterodactyls  and  in  no  other  animals  of  which  I  have  any 
knowledge.  The  entire  length  of  the  bone  must  have  been  about  350  or 
400  mm.,  and  while  the  walls  are  unusually  thick,  they  are  not  propor- 
tionally much  more  so  than  in  Dermodactylus,  the  type  of  which  I 
distinctly  remember.  Dermodactylus  is  from  the  so-called  fresh-water 
beds  of  the  Wyoming  Jurassic,  which  I  have  long  believed  to  be  con- 
temporaneous with  the  Comanche  beds  of  Kansas,  and  which  I  correlate 
with  the  Wealden  of  Europe.  The  forms  cannot  be  the  same,  since  this 
is  very  much  larger. 

May  14,  1903. 


In  an  article  by  Mr.  F.  A.  Lucas  in  the  Report  of  the  Smithsonian 
Institution  for  1901,  there  is  given  an  excellent  drawing  of  a  skull  of 
Pteranodon  {Ornithostomd),  made  "from  a  specimen  in  the  Yale  University 
Museum."  From  my  recollection  of  various  peculiarities  shown  in  the 
figure,  as  also  from  certain  accidental  peculiarities,  such  as  the  fracture 
of  the  infra-narial  bar,  faithfully  reproduced  in  Professor  Marsh's  drawings, 
I  have  very  little  hesitation  in  saying  that  the  specimen  there  illustrated 
is  the  type  of  the  genus  Pteranodon,  upon  which  was  based  the  figure  so 
long  current  in  text-books.  Should  I  be  in  error  in  this  identification,  I 
shall  be  glad  to  be  corrected,  hoping,  however,  in  that  case,  that  a  true 
figure  of  the  type  specimen  may  be  published. 

In  the  summer  of  1891,  Professor  E.  C.  Case  and  myself  uncovered 
from  the  firm  yellow  chalk  of  western  Kansas,  the  uninjured  posterior 
part  of  a  skull  of  Pteranodon,  with  its  sagittal-crest  entire  and  evenly 
rounded.  A  figure  of  this  specimen  was  given  in  PI.  I,  Vol.  I,  of  the 
Kansas  University  Quarterly,  to  which  I  beg  to  refer  the  reader.  The 
specimen  is  now  preserved  on  a  slab  in  the  museum  of  the  University  of 
Kansas,  and  I  doubt  not  that  the  crest  as  disclosed  from  the  matrix  and 
as  represented  in  the  figure,  is  all  that  the  animal  possessed  in  life.  Mr. 
G.  F.  Eaton,  however,  in  the  July  number  of  the  American  Journal  of 
Science  takes  me  to  task  for  criticising  the  original  figures  of  Pteranodon, 
which  he  admits  were  faulty,  and  for  my  "restoration"  of  the  skull,  assert- 
ing that  I  was  wrong.  He  now  adds  to  the  type  a  much  longer  crest  than 
did  the  author.  The  basis  for  Professor  Marsh's  restoration  is  shown  in 
Mr.  Lucas's  plate,  if  my  identification  is  correct,  and  the  drawing  has 
been  faithfully  made. 


162  Field  Columbian  Museum — Geology,  Vol.  II. 

I  do  not  criticise  Professor  Marsh  for  making  the  restoration  as  he 
did;  he  was  perhaps  justified,  though  it  might  have  been  better  had  he 
stated  how  much  of  the  restoration  was  conjectural,  and  had  also  pub- 
lished a  figure  of  the  specimen  as  it  actually  was. 

In  his  present  paper  Mr.  Eaton  says:  "At  the  present  time  of  writing 
an  incomplete  Pterodactyl  skull  is  being  worked  out  at  the  Yale  Museum, 
which  will,  in  all  probability  prove  to  be  that  of  Nyctodactylus  Marsh. 
The  crest,  which  is  apparently  entire,  is  of  small  size  compared  with  that 
of  Pteranodon,  the  measurement  from  occipital  condyle  to  tip  of  crest 
being  only  49  mm.,  while  the  length  from  occipital  condyle  to  tip  of 
beak  was  approximately  45  cm.  In  general  the  skull  compares  favorably 
with  that  shown  in  Williston's  restoration  of  Nyctodactylus,  given  in  the 
American  Journal  of  Anatomy,  Vol.  I,  No.  3,  May  26,  1902,  where  he 
states  that  the  outline  is  taken  in  part  from  a  specimen  of  Pteranodon 
Marsh,  or  Omithostoma  Seeley,  as  the  genus  was  then  called.  It  is  there- 
fore fair  to  infer  that  the  apparent  similarity  of  the  two  genera  led  Wil- 
liston  to  draw  inadvertently  upon  the  characters  of  Nyctodactylus  in  mak- 
ing his  restoration  of  Pteranodon." 

Had  Mr.  Eaton  done  me  the  honor  to  have  read  more  attentively  the 
article  which  he  quotes;  or  had  he  examined  the  extended  article  on  the 
skull  of  Nyctodactylus  with  plates,  published  in  the  Journal  of  Geology  for 
August,  1902;  or  even  had  he  examined  the  figure  of  the  skull  in  Zittel's 
text-book  of  Paleontology,  published  last  autumn,  of  all  of  which  he 
seems  strangely  ignorant,  he  would  have  learned  that  Nyctodactylus  has 
no  crest  whatever,  not  even  a  vestige  of  one!  It  is  very  evident,  therefore, 
that  Mr.  Eaton  has  made  the  very  error  which  he  so  freely  suggests  I 
have  made,  and  that  his  specimen  is  in  reality  a  Pteranodon/  I  am 
pleased  to  learn  that  its  "apparently  entire"  "crest"  compares  favorably 
with  that  which  I  have  assigned  to  the  same  genus. 

Now,  since  his  own  observations  show  that  Pteranodon  may  have  a 
short  crest,  very  much  as  I  have  figured  it,  it  will  be  of  interest  to  learn 
more  fully  his  reasons  for  attaching  the  elongated  crest  he  has  to  the  skull 
as  shown  in  Mr.  Lucas's  figure.  I  furthermore  note  that  Mr.  Eaton  con- 
tinues, in  his  "restoration"  of  the  skull  of  Pteranodon,  the  gravest  of  the 
inaccuracies  of  the  original  figures,  the  absence  of  the  supratemporal 
fossa  and  arch.  If  he  is  correct  in  this,  the  original  reference  of  the 
genus  to  a  distinct  order  of  reptiles  was  justified.  But  we  will  await  fur- 
ther evidence  before  assuming  that  he  is,  and  meanwhile,  it  will  be  unfor- 
tunate if  his  restoration  finds  currency. 

Inasmuch  as  Mr.  Eaton  has  so  clearly  shown  his  ignorance  of  recent 
and  very  accessible  literature  on  the  subject,  it  is  too  much  to  expect  that 
he  would  have  mentioned  the  fact  that  the  pelvis  of  Pteranodon  has  been 


On  the  Osteology  of  Nyctosaurus  163 

described  and  partly  figured  without  certain  errors  into  which  he  has 
fallen,  and  that  the  peculiar  "spiral"  condyles  of  both  Pteranodon  and 
Nyctodactylus  have  likewise  been  described  and  figured,  without,  however, 
their  having  suggested  to  any  one  the  probability  that  the  animals  dis- 
located their  jaws  in  deglutition. 


Plate  XL. 
Nyctosaurus  gracilis. 


View  of  part  of  specimen,  showing  sternum,  pelvis,  dorsal  vertebrae,  ribs 
and  arm  bones.     Natural  size. 


FIELD  COLUMBIAN   MUSEUM. 


GEOLOGY, PLATE  XL. 


Nyctosaurus  gracilis  Marsh. 


.ux  = 
.auioAflo  eu 


. 


in  gri] 


■    . 
'  i!  [aim  I, 


Plate  XLI. 
Nyctosaurus  gracilis. 


Fig.  I.  Dorsal  vertebrae,  ribs,  and  pelvis;  about  three-fifths  natural  size, 
r,  ribs;  dv,  lumbar  or  false  sacral;  s,  sacrum;  ip,  ischio-pubis;  ob,  obturator  for- 
amen; il,  ilium;  ftp,  prepubes. 

Fig.  2.    Abdominal  ribs.   About  three-fifths  natural  size. 

Fig.  3.     Atlanto-axis,  from  the  side.    Twice  natural  size. 

Fig.  4.    The  same  from  behind,  partly  restored. 

Fig.  5.  The  same,  from  in  front:  a,  atlantal  neurapophysis;  ac,  axial  cen- 
trum; at,  atlantal  intercentrum;  axi,  axial  intercentrum;  ^,ball  of  axis;  o,  odontoid; 
ftz,  postzygapophysis. 

Fig.  6.     Hyoid  bone.    Three  times  natural  size. 

Fig.  7.     Extremity  a  of  Fig.  6,  more  enlarged,  from  the  side. 


FIELD  COLUMBIAN   MUSEUM. 


GEOLOGY,  PLATE  XLI. 


S.  W.  W.  del. 


Nyctosaurus. 


Plate  XLII. 
Nyctosaurus  gracilis. 


Fig.  i.     Sternum,  from  below.    Three-fifths  natural  size. 
Fig.  2.     Left  radius,  ulna,  and  carpus,  from  inner  side,  the  carpus  somewhat 
displaced:    a,  radius;  b,  ulna;  c,  proximal  carpal;  d,  distal  carpal. 
Fig.  3.     Right  lateral  carpal  or  first  metacarpal. 
Fig.  4.     Right  pteroid  bone,  from  in  front. 
Fig.  5.     Right  pteroid,  from  behind. 
Fig.  6.     Small  metacarpal.    Twice  natural  size. 
Fig.  7.     Left  humerus,  from  within. 
All  the  figures,  except  as  stated,  natural  size. 


FIELD  COLUMBIAN   MUSEUM. 


GEOLOGY,  PLATE  XLII. 


S.  W.  W.  del. 


Nyctosaurus. 


. 


I 


■ 


'     .a§n 


■■■ 
■ 


Plate  XLIII. 

Fig.  i.  Left  femur  of  Pteranodon  ingens,  somewhat  obliquely  compressed, 
from  in  front  showing  dermal  markings.    One-half  natural  size. 

Fig.  2.     The  same,  posterior  surface.     One-half  natural  size. 

Fig.  3.    The  same,  distal  end.    One-half  natural  size. 

Fig.  4.     Right  femur  of  Nyctosaurus gracilis,  from  in  front.     Natural  size. 

Fig.  5.    The  same,  from  behind.     Natural  size. 

Fig.  6.  Left  coraco-scapula  of  Nyctosaurus  gracilis;  s,  scapula;  c,  cora- 
coid;  a,  process  of  scapula.     Natural  size. 

Fig.  7.  First  dorsal  vertebra  of  Nyctosaurus  gracilis,  from  in  front.  Twice 
natural  size. 

Fig.  8.  Eighth  cervical  vertebra  of  Nyctosaurus  gracilis,  as  compressed, 
obliquely  from  behind:  s,  spine;  b,  ball;  d,  diapophysis;  e,  exapophysis.  Twice 
natural  size. 

Fig.  9.     Metatarsal  of  Nyctosaurus  gracilis.     Natural  size. 

Fig.  10.  Right  distal  carpal  of  Nyctosaurus  gracilis,  obliquely  from  behind. 
Natural  size. 

Fig.  11.  Proximal  caudal  or  caudo-sacral  vertebra  of  Nyctosaurus  gracilis, 
from  above.     Natural  size. 


FIELD  COLUMBIAN   MUSEUM. 


GEOLOGY,  PLATE  XLIII. 


S.  W.  W.  del. 


Pteranodon,  Nyctosaiims. 


. 


Plate  XLIV. 

Fig.  i.  Right  first  wing  phalange  of  Nyctosaurus  gracilis.  One-half  nat- 
ural size. 

Fig.  2.  Right  wing  metacarpal  of  Nyctosaurus  gracilis,  from  below.  One- 
half  natural  size. 

Fig.  3.     Tibia  of  Nyctosaurus  gracilis,  from  the  side.     Natural  size. 

Fig.  4.  Left  femur  of  Pteranodon  occidentalism.)  Marsh,  from  behind.  One- 
half  natural  size. 

Fig.  5.  Right  second  wing  phalange  of  Nyctosaurus  gracilis,  from  behind. 
One-half  natural  size. 

Fig.  6.  Posterior  cervical  vertebra  of  Nyctosaurus  gracilis,  from  the  side. 
Twice  natural  size. 

Fig.  7.  Fifth  cervical  vertebra  of  Nyctosaurus  gracilis,  from  above.  Twice 
natural  size. 

Fig.  8.  Lateral  carpal  of  Pteranodon  ingens,  after  Cope.  One-half  nat- 
ural size. 


FIELD  COLUMBIAN   MUSEUM. 


GEOLOGY,  PLATE  XLIV. 


S.  W.  W.  del. 


Pteranodon,  Nyctosaurus. 


\o 


